What We Know About Black Storks

Cameras Watching over Black Storks nest
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Re: What We Know About Black Storks

Post by Biker » August 21st, 2019, 12:01 am


Extremely Sad Birds Show How a Population Can Die From Loneliness
"Waiting for a partner. Often in vain."

--- Black storks in Estonia are experiencing a situation all single people have lived through: Taking stock of your life and realizing that you’re completely, utterly alone. Unlike lonely millennials, these monogamous birds don’t have the option of swiping right for a last-ditch hookup, which is deeply unfortunate. As new research on this threatened species indicates, it could be possible for an entire population to die from loneliness.

--- The question lonely individuals can’t help but ask is: Why am I single? The most plausible reason for all those single storks, the team writes, is that there’s an unbalanced sex ratio in the population — likely too many single males compared to females. This hypothesis is consistent with how some of the frustrated singles were acting: harassing neighboring couples at their nests. (It’s hard to get a clear answer about sex ratios, however, because in this species, both sexes look the same.)

read more
https://www.inverse.com/article/53122-b ... you-and-me

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Post by Biker » August 21st, 2019, 4:09 pm


The impact of human activity and habitat characteristics on the distribution of Black Storks Ciconia nigra on wintering grounds in West Africa

https://www.tandfonline.com/doi/pdf/10. ... ccess=true

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Post by Anne7 » August 24th, 2019, 1:41 pm

Liz, Ari and Biker, many thanks! :thumbs:
Pica :hi:
Ari19 wrote:
August 15th, 2019, 5:59 pm
Wow, Anne7! That is such an amount!
One issue though... I’m afraid I won’t be able to tell if the article I want to post is already here. How will we prevent doubles? :puzzled:
:hi: Yes, Ari, it becomes hard to see if we don't post the same article twice. :nod:
What I do when I have doubts: I copy part of the new title (keywords) and paste it (between " " ) in the search tool (on top at the right).
If the same article has already been posted, it will be found this way.

Once everything will be arranged according to their theme, the checking on "doubles" will probably be easier.

Research into Bird Migration

Posted here: viewtopic.php?p=622836#p622836
Wind blows young migrant birds to all corners of Africa
University of Amsterdam
Migrant birds that breed in the same area in Europe spread out across all of Africa during the northern winter. A new satellite-tracking study shows that the destination of individual birds is largely determined by the wind conditions they encounter during their first migration. The results were made available open access in the peer-reviewed journal Proceedings of the Royal Society B.

https://phys.org/news/2017-05-young-mig ... .html#nRlv

Posted here: viewtopic.php?p=622836#p622836
Migratory Birds May Come Programmed With a Genetic Google Maps
These hybrid avians inherit some mixed directional messages

Many young birds migrate successfully without help from older birds who have made the trip before. The implication is that migration instructions - perhaps even some sort of map of astronomical or geographical references - are somehow written upon the genes inherited from their parents. Just how maps can be coded into gene structure is anyone's guess. In fact, since the DNA in the genes seems to code only for protein synthesis, the locations and characters of inheritable maps are still not understood.
For example, the Swainson’s thrush is split into two subgroups that migrate along very different routes. Every spring both subgroups return to Canada and— here’s the key — they sometimes interbreed.
The researchers found that the 'hybrid' offspring favoured a flyway that was in between those of the two subgroups! Since the hybrid thrushes couldn’t have learned that middle road, it seems that the birds were guided by a mixture of genetic instructions inherited from both parents.

Read more: https://www.smithsonianmag.com/science- ... iuc2rPB.99

Posted here: viewtopic.php?p=622836#p622836
Mixed genes mix up the migrations of 'hybrid' birds
Researcher Kira Delmore
Mixed genes appear to drive hybrid birds to select more difficult routes than their parent species, according to new research from University of British Columbia zoologists. “Instead of taking well-trodden paths through fertile areas, these birds choose to scale mountains and cross deserts,” says UBC researcher Kira Delmore.
https://news.ubc.ca/2014/07/22/mixed-ge ... rid-birds/

Posted here: viewtopic.php?p=618022#p618022
Air speeds of migrating birds observed by ornithodolite and compared with predictions from flight theory
C. J. Pennycuick , Susanne Åkesson and Anders Hedenström
We measured the air speeds of 31 bird species, for which we had body mass and wing measurements, migrating along the east coast of Sweden in autumn, using a Vectronix Vector 21 ornithodolite and a Gill WindSonic anemometer. We expected each species’ average air speed to exceed its calculated minimum-power speed (Vmp), and to fall below its maximum-range speed (Vmr), but found some exceptions to both limits. To resolve these discrepancies, we first reduced the assumed induced power factor for all species from 1.2 to 0.9, attributing this to splayed and up-turned primary feathers, and then assigned body drag coefficients for different species down to 0.060 for small waders, and up to 0.12 for the mute swan, in the Reynolds number range 25 000–250 000. These results will be used to amend the default values in existing software that estimates fuel consumption in migration, energy heights on arrival and other aspects of flight performance, using classical aeronautical theory. The body drag coefficients are central to range calculations. Although they cannot be measured on dead bird bodies, they could be checked against wind tunnel measurements on living birds, using existing methods.
"... Usually, as thermals do not form over water, birds fly low above the water. ..."
"... Figure 2 shows that the average flying height was less than 50m above the water surface in all 31 species in our sample, and less than 10m in 16 of them. ... As most (observed) tracks were several hundred metres long, these low flying heights constrained the flight paths to be nearly horizontal, as assumed by the theory. ..."
Mean flying heights above the water surface for 31 species in our sample
https://royalsocietypublishing.org/doi/ ... .2013.0419

Avian navigation: from historical to modern concepts
© 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved
Studies on avian navigation began at the end of the 19th century with testing various hypotheses, followed by large-scale displacement experiments to assess the capacity of the birds’ navigational abilities. In the 1950s, the first theoretical concepts were published. Kramer proposed his ‘Map-and-Compass’model, assuming that birds establish the direction to a distant goal with the help of an external reference, a compass. The model describes homing as a two-step process, with the first step determining the direction to the goal as a compass course and the second step locating this course with the help of a compass. This model was widely accepted when numerous experiments with clock-shifted pigeons demonstrated the use of the sun compass, and thus a general involvement of compass orientation, in homing. The ‘map’ step is assumed to use local site-specific information, which led to the idea of a ‘gridmap’ based on environmental gradients. Kramer’s model still forms the basis of our present concept on avian homing, yet route integration with the help of an external reference provides an alternative strategy to determine the home course, and the magnetic compass is a second compass mechanism available to birds. These mechanisms are interrelated by ontogenetic learning processes. A two-step process, with the first step providing the compass course and the second step locating this course with the help of a compass, appears to be a common feature of avian navigation tasks, yet the origin of the compass courses differs between tasks according to their nature, with courses acquired by experience for flights within the home range, courses based on navigational processes for returning home, and courses derived from genetically coded information in first-time migrants. Compass orientation thus forms the backbone of the avian navigational system.
https://www.academia.edu/24491372/Avian ... n_concepts

Posted here: viewtopic.php?p=613362#p613362
How Do Birds Migrate Over Thousands Of Kilometers Without Ever Getting Lost?
John Staughton in Science ABC
In many parts of the world, people can look up at certain times of the day and see huge flocks of migrating birds passing overhead. It has been noted by researchers and ornithologists throughout history that birds often take the same migratory paths year after year. Furthermore, many of them return to the exact same locations at either end of their migrations, spots sometimes separated by tens of thousands of miles!
There are about 10,000 bird species in the world, and nearly 20% of them are long-distance migrants. These migratory species typically move in a north-south directional pattern between their “breeding” grounds and their “wintering” grounds. Migration primarily occurs due to the need to reproduce, the availability of food, and increased/decreased threats of predation.
The size of migratory routes can vary widely, from as little as a few hundred meters to well over 50,000 miles. These migratory patterns have been recognized by humans for more than 3,000 years, yet this ability in birds remains an incredibly mysterious skill. Certain conclusions and observations have been made to clue us into this special secret, but there are still a lot of questions. ...
Vision-based magnetoreception
"One of the more complicated theories to explain avian migration involves bird species’ ability to detect the magnetic fields of the Earth, and subsequently follow those fields to their ultimate destination. This ability to use “invisible” waves was hard for some ornithologists to swallow, but it was proposed that some bird beaks contain magnetic particles that act as a compass. Recently, this theory has fallen out of fashion, replaced by the theory of vision-based magnetoreception.
The concept of vision-based magnetoreception means that birds can “see” magnetic fields and align themselves with the direction of the field they want to travel. If a bird is migrating south, it will align with a south-facing magnetic field and be on its way. Experiments in laboratories have actually generated artificial “magnetic south”, and birds moved in that direction. ..."
Simple Avian Eye Diagram (Photo Credit: www.the-scientist.com)
A Quantum Explanation?
"The last great mystery to vision-based magnetoreception is how this sort of magnetic field sensor can be present inside a bird’s retinal cells. One of the most recent theories suggests that quantum mechanics may provide the answer. For such a detector of strength AND direction, some mechanism would need to be in place to amplify the relatively weak magnetic effects of the Earth enough to be detected.
In quantum mechanics, a radical pair consists of two simultaneously created molecules, each with one electron of opposing, associated spin that makes these pairs highly sensitive to outside forces and magnetic fields.
When a specific light-sensitive protein found in the retinal cells of birds, cryptochrome, is exposed to certain wavelengths of green or blue light, it can organically create these radical pairs. Magnetoreception like this is the latest field of quantum biology, and one that is currently being studied around the world."

Lateralization of the Avian Magnetic Compass: Analysis of Its Early Plasticity
Dennis Gehring, Onur Güntürkün, Wolfgang Wiltschko and Roswitha Wiltschko
Academic Editor: Lesley J. Rogers, received 26 March 2017
Abstract: In European Robins, Erithacus rubecula, the magnetic compass is lateralized in favor of the right eye/left hemisphere of the brain. This lateralization develops during the first winter and initially shows a great plasticity. During the first spring migration, it can be temporarily removed by covering the right eye. In the present paper, we used the migratory orientation of robins to analyze the circumstances under which the lateralization can be undone. Already a period of 11/2 h being monocularly left-eyed before tests began proved sufficient to restore the ability to use the left eye for orientation, but this effect was rather short-lived, as lateralization recurred again within the next 11/2 h. Interpretable magnetic information mediated by the left eye was necessary for removing the lateralization. In addition, monocularly, the left eye seeing robins could adjust to magnetic intensities outside the normal functional window, but this ability was not transferred to the “right-eye system”. Our results make it clear that asymmetry of magnetic compass perception is amenable to short-term changes, depending on lateralized stimulation. This could mean that the left hemispheric dominance for the analysis of magnetic compass information depends on lateralized interhemispheric interactions that in young birds can swiftly be altered by environmental effects.
https://www.bio.psy.ruhr-uni-bochum.de/ ... ompass.pdf

Roswitha Wiltschko
Journal of Comparative Physiology A
July 2017, Volume 203, Issue 6–7, pp 455–463

Experiments with migrating birds displaced during autumn migration outside their normal migration corridor reveal two different navigational strategies: adult migrants compensate for the displacement, and head towards their traditional wintering areas, whereas young first-time migrants continue in their migratory direction. Young birds are guided to their still unknown goal by a genetically coded migration program that indicates duration and direction(s) of the migratory flight by controlling the amount of migratory restlessness and the compass course(s) with respect to the geomagnetic field and celestial rotation. Adult migrants that have already wintered and are familiar with the goal area approach the goal by true navigation, specifically heading towards it and changing their course correspondingly after displacement. During their first journey, young birds experience the distribution of potential navigational factors en route and in their winter home, which allows them to truly navigate on their next migrations. The navigational factors used appear to include magnetic intensity as a component in their multi-modal navigational ‘map’; olfactory input is also involved, even if it is not yet entirely clear in what way. The mechanisms of migratory birds for true navigation over long distances appear to be in principle similar to those discussed for by homing pigeons.
https://www.researchgate.net/publicatio ... Navigation

Directional orientation of birds by the magnetic field under different light conditions
Roswitha Wiltschko, Katrin Stapput, Peter Thalau and Wolfgang Wiltschko
in Journal of The Royal Society Interface; 7 Suppl 2(Suppl. 2):S163-77 · October 2009

This paper reviews the directional orientation of birds with the help of the geomagnetic fieldunder various light conditions. Two fundamentally different types of response can be distinguished. (i) Compass orientation controlled by the inclination compass that allows birds to locate courses of different origin. This is restricted to a narrow functional window around the total intensity of the local geomagnetic field and requires light from the short-wavelength part of the spectrum. The compass is based on radical-pair processes in the right eye;magnetite-based receptors in the beak are not involved. Compass orientation is observed under ‘white’ and low-level monochromatic light from ultraviolet (UV) to about 565 nm green light. (ii) ‘Fixed direction’ responses occur under artificial light conditions such as more intense monochromatic light, when 590 nm yellow light is added to short-wavelength light, and in total darkness. The manifestation of these responses depends on the ambient light regime and is ‘fixed’ in the sense of not showing the normal change between spring and autumn; their biological significance is unclear. In contrast to compass orientation,fixed-direction responses are polar magnetic responses and occur within a wide range of magnetic intensities. They are disrupted by local anaesthesia of the upper beak, which indicates that the respective magnetic information is mediated by iron-based receptors located there. The influence of light conditions on the two types of response suggests complex interactions between magnetoreceptors in the right eye, those in the upper beak and the visual system.
https://www.researchgate.net/publicatio ... conditions

Resonance effects indicate a radical-pair mechanism for avian magnetic compass
Thorsten Ritz, Peter Thalau, John B. Phillips, Roswitha Wiltschko & Wolfgang Wiltschko
Migratory birds are known to use the geomagnetic field as a source of compass information. There are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite, the other a magnetically sensitive chemical reaction6–8. Here we show that oscillating magnetic fields disrupt the magnetic orientation behaviour of migratory birds. Robins were disoriented when exposed to a vertically aligned broadband (0.1–10 MHz) or a single-frequency (7-MHz) field in addition to the geomagnetic field. Moreover, in the 7-MHz oscillating field, this effect depended on the angle between the oscillating and the geomagnetic fields. The birds exhibited seasonally appropriate migratory orientation when the oscillating field was parallel to the geomagnetic field, but were disoriented when it was presented at a 248 or 488 angle. These results are consistent with a resonance effect on singlet-triplet transitions and suggest a magnetic compass based on a radical- pair mechanism
https://s3.amazonaws.com/academia.edu.d ... cd2dbc24eb

The evolution of bird migration - A synthesis
Volker Salewski, Bruno Bruderer
Abstract: We approach the problem of the evolution of bird migration by asking whether migration evolves towards new breeding areas or towards survival areas in the non-breeding season. Thus, we avoid the ambiguity of the usually discussed "southern-home-theory" or "northern-home-theory". We argue that migration evolved in birds that spread to seasonal habitats through gradual dispersal to enhance survival during the non-breeding season; this in contrast to the alternative idea suggesting that migration evolved towards new breeding areas to increase reproductive success. Our synthesis is based on the threshold model explaining how migratory traits can change rapidly through microevolutionary processes. Our model brings former theories together and explains how bird migration, with the appropriate direction and time program, evolves through selection after genetically non-directed events such as dispersal and colonisation. The model does not need the former untested assumptions such as competition as a reason for migration and for the disappearance of sedentary populations or higher reproductive success in temperate breeding areas. Our theory offers answers to questions such as how birds with a southern origin may gradually reach northern latitudes, why migration routes may follow historical expansion routes and why birds leave an area for the non-breeding season and move back instead of breeding on their wintering grounds. The theory proposes gradual change through selection and not sudden changes such as long distance dispersal or mutations and can be applied to migration at all latitudes and in all directions. The scenario provides a reasonable concept to understand most of the existing migratory phenomena on the basis of the ecology and genetics of migratory behaviour.
https://www.researchgate.net/publicatio ... _synthesis

How do migrating birds find their way?
Ying XIONG, TianLong CAI, FuMin LEI
Abstract: Bird are one of the most abundant and widespread groups in the world. With many specialized structures, such as plumage, air sacs, and hollow bones, most bird species have got flight ability to adapt various niches. Therefore, bird can migrate between wintering and breeding ground, which is usually a long distance, and it’s called migration. Bird navigation is important in migration and is a complex process, which attracts many scientists to dig in how bird finds its way. Since 1873, Charles Darwin has ever mentioned that bird might take the method of dead reckoning on a long-distance migration like human, but at that time no one made further progress. Until 1950s, Kramer firstly found that Common Starling (Sturnus vulgaris) can respond to solar azimuth via mirror test. From then on, many experiments revealed that at least four navigation mechanisms are used in bird migration via more than nine external factors. They are: (i) celestial navigation, celestial clues (e.g. solar azimuth, star position, and polarized light) are used during migration period. (ii) Olfactory navigation, odor distributing in the air forms odorous gradient map or mosaic map which can be detected, or can activate directly certain mechanism to navigate. (iii) Auditory navigation, infrasound (0.05 Hz) produced by mountains and rivers generate sonic gradient map. And (iv) magnetic navigation, geomagnetic field can be detected via magnetic materials or chemical magnetoreception to find correct directions. Although many scientists approve that magnetic navigation may be the main mechanism to orientate and navigate, bird has never taken just one mechanism to migrate. Indeed, many species also use the other three mechanisms to calibrate direction, for example, Savannah Sparrow (Passerculus sandwichensis) can use polarized light to calibrate the magnetic compass at both sunrise and sunset. Different external clues correspond to different sense organs, so various brain areas should deal with information from different navigation mechanisms. The hippocampus participates in spatial perception and manages anything about celestial navigation via the tectofugal visual pathway and the thalamofugal visual pathway. The piriform cortex (CPi) is the main area to receive stimulation from olfactory bulb and determines how to migrate after receiving olfactory clues. Nervous systems of magnetic navigation include two parts which are trigeminus system and Cluster N. Despite the controversy whether there are some magnetic materials on bird, many experimental evidences have proved that magnetic materials detecting geomagnetic field involve to Trigeminus system. Cluster N, however, is an active area when bird migrates at night and it has an important role in transferring information from chemical magnetoreception to the hippocampus. As illustrated above, navigation mechanisms can get full information from many clues, and then, different brain areas trade off those and co-operate each other to make an elaborate map. Bird navigation involves the receptors to environment and the response of nervous system, so many issues are still maintained. The exact mechanism will be revealed with the new techniques and model animal applied.
http://engine.scichina.com/doi/10.1360/ ... ltextltext

How do migratory birds find their way ?
Biologists on board of the "Alcyon", the boat that undertook an expedition "from the Mediterranean Sea to the Spitzberg", take turns to identify and count all the birds they meet. Among them, many are migratory birds.
It is springtime, that's why! Migratory birds are coming back to cooler areas to breed and build their nest. These birds often make incredible journeys and come back, year after year, to the same place.
http://www.educapoles.org/news/news_det ... _their_way

Wind tunnel as a tool in bird migration research
Anders Hedenström, Åke Lindström
Abstract: Wind tunnels, in which birds fly against an artificially generated air flow, have since long been used to evaluate aerodynamic properties of steady bird flight. A new generation of wind tunnels has also allowed the many processes associated with migratory flights to be studied in captivity. We review how wind tunnel studies of aerodynamics and migratory performance together have helped advancing our understanding of bird migration. Current migration theory is based on the power‐speed relationship of flight as well as flight range equations, both of which can be evaluated using birds flying in wind tunnels. In addition, and depending on wind tunnel properties, performance during gliding and climbing flight, and effects of air pressure, humidity and turbulence on bird flight has been measured. Long‐distance migrant species have been flown repeatedly for up to 16 h non‐stop, allowing detailed studies of the energy expenditure, fuel composition, protein turnover, water balance, immunocompetence and stress associated with sustained migratory flights. In addition, wind tunnels allow the fuelling periods between migratory flights to be studied from new angles. We end our review by suggesting several important topics for future wind tunnel studies, ranging from on of the key questions remaining, the efficiency at which chemical power in converted to mechanical power, to new useful avenues, such as improving and calibrating the techniques used for tracking of individual birds in the wild.
https://onlinelibrary.wiley.com/doi/abs ... /jav.01363

Possible linkage between neuronal recruitment and flight distance in migratory birds
Shay Barkan, Uri Roll, Yoram Yom-Tov, Leonard I. Wassenaar & Anat Barnea
Abstract: New neuronal recruitment in an adult animal’s brain is presumed to contribute to brain plasticity and increase the animal’s ability to contend with new and changing environments. During long-distance migration, birds migrating greater distances are exposed to more diverse spatial information. Thus, we hypothesized that greater migration distance in birds would correlate with the recruitment of new neurons into the brain regions involved with migratory navigation. We tested this hypothesis on two Palearctic migrants - reed warblers (Acrocephalus scirpaceus) and turtle doves (Streptopelia turtur), caught in Israel while returning from Africa in spring and summer. Birds were injected with a neuronal birth marker and later inspected for new neurons in brain regions known to play a role in navigation - the hippocampus and nidopallium caudolateral. We calculated the migration distance of each individual by matching feather isotopic values (δ2H and δ13C) to winter base-maps of these isotopes in Africa. Our findings suggest a positive correlation between migration distance and new neuronal recruitment in two brain regions - the hippocampus in reed warblers and nidopallium caudolateral in turtle doves. This multidisciplinary approach provides new insights into the ability of the avian brain to adapt to different migration challenges.

Magnetoreception in Birds and Its Use for Long-Distance Migration
Henrik Mouritsen
Abstract: The Earth’s magnetic field provides potentially useful information, which birds could use for directional and/or positional information. It has been clearly demonstrated that birds are able to sense the compass direction of the Earth’s magnetic field and that they can use this information as part of a compass sense. Magnetic information could also be useful as part of a map sense, and there is a growing body of evidence that birds are able to determine their approximate position on the Earth on the basis of geomagnetic cues. In addition to direct uses for orientation and navigation, magnetic information also seems to be able to influence other physiological processes, such as fattening and migratory motivation, as a trigger for changes in behaviour. Although the behavioural responses to geomagnetic cues are relatively well understood, the physiological mechanisms enabling birds to sense the Earth's magnetic field are only starting to be understood, and understanding the magnetic sense(s) of animals, including birds, remains one of the most significant unsolved problems in biology. It is very challenging to sense magnetic fields as weak as that of the Earth using only biologically available materials. Only two basic mechanisms are considered theoretically viable in terrestrial animals: iron-mineral-based magnetoreception and radical-pair based magnetoreception. On the basis of current scientific evidence, iron-mineral-based magnetoreception and radical-pair-based magnetoreception mechanisms seem to exist in birds, but they seem to be used for different purposes. Plausible primary sensory molecules and a few brain areas involved in processing magnetic information have been identified in birds for each of these two types of magnetic senses. Nevertheless, we are still far away from understanding the detailed function of any of the at least two different magnetic senses existing in some if not all bird species, and, at present, no primary sensory structure has been identified beyond reasonable doubt to be the source of avian magnetoreception. This is an exciting but challenging field in which several major discoveries are likely to be made in the next 1–2 decades.
https://www.researchgate.net/profile/He ... ee284a.pdf

A Model for Photoreceptor-Based Magnetoreception in Birds
Thorsten Ritz, Salih Adem, Klaus Schulten
Abstract: A large variety of animals has the ability to sense the geomagnetic field and utilize it as a source of directional (compass) information. It is not known by which biophysical mechanism this magnetoreception is achieved. We investigate the possibility that magnetoreception involves radical-pair processes that are governed by anisotropic hyperfine coupling between (unpaired) electron and nuclear spins. We will show theoretically that fields of geomagnetic field strength and weaker can produce significantly different reaction yields for different alignments of the radical pairs with the magnetic field. As a model for a magnetic sensory organ we propose a system of radical pairs being 1) orientationally ordered in a molecular substrate and 2) exhibiting changes in the reaction yields that affect the visual transduction pathway. We evaluate three-dimensional visual modulation patterns that can arise from the influence of the geomagnetic field on radical-pair systems. The variations of these patterns with orientation and field strength can furnish the magnetic compass ability of birds with the same characteristics as observed in behavioural experiments. We propose that the recently discovered photoreceptor cryptochrome is part of the magnetoreception system and suggest further studies to prove or disprove this hypothesis.
https://www.sciencedirect.com/science/a ... 950076629X

Long-distance navigation and magnetoreception in migratory animals
Henrik Mouritsen
Naturevolume 558, pages 50–59 (2018)

For centuries, humans have been fascinated by how migratory animals find their way over thousands of kilometres. Here, I review the mechanisms used in animal orientation and navigation with a particular focus on long-distance migrants and magnetoreception. I contend that any long-distance navigational task consists of three phases and that no single cue or mechanism will enable animals to navigate with pinpoint accuracy over thousands of kilometres. Multiscale and multisensory cue integration in the brain is needed. I conclude by raising twenty important mechanistic questions related to long-distance animal navigation that should be solved over the next twenty years.

Magnetic compass of migratory Savannah sparrows is calibrated by skylight polarization at sunrise and sunset
Rachel Muheim Æ Susanne A ̊ kesson Æ John B. Phillips
© Dt. Ornithologen-Gesellschaft e.V. 2007

Abstract Migratory birds use compass systems derived from the geomagnetic field, the stars, the sun and polarized light patterns. We tested whether birds use a single underlying reference system for calibration of these compasses and, specifically, whether sunset and sunrise polarized light cues from the region of the sky near the horizon are used to calibrate the magnetic compass. We carried out orientation experiments with Savannah sparrows, Passerculus sandwichensis, in Alaska during autumn migration 2005, and compared the magnetic orientations of individual birds before and after exposure to conflicting information between magnetic and celestial cues. Birds exposed to an artificially shifted polarization pattern (±90° shift relative to the natural condition) for 1 h at local sunrise or sunset recalibrated their magnetic compass, but only when given access to the artificial polarization pattern near the horizon. Birds exposed to a 90° clockwise-shifted magnetic field for 1 h at solar noon did not recalibrate their magnetic compass. These results indicate that migratory birds calibrate their magnetic compass using the skylight polarization pattern vertically intersecting the horizon at sunrise and sunset. In conjunction with earlier work showing that sun and star compass calibrations are secondarily derived from magnetic and polarized light cues, our findings suggest that polarized light cues near the horizon at sunrise and sunset provide the primary calibration reference for the compass systems of migratory songbirds.
https://web.archive.org/web/20081217154 ... 202007.pdf

Posted here: viewtopic.php?p=613362#p613362
How do migratory birds find their way ?
"This question still interests many scientists. It has been shown that birds use several orientation tools.
They can use the sun, for example, which means that they permanently "know" what time it is, in order to know the right direction on the basis of the sun's position. They are also sensible to the ultraviolet rays which penetrate the clouds but are invisible for human beings. (So they see the sun's position also on a cloudy day.) Even the nocturnal birds use the position of the sun at sunset to know their position.
Nocturnal birds also use the stars. This has been proved by letting birds fly in a planetarium and changing the stars' position.
Another tool is the earth's magnetic field (earth's north and south magnetic poles). Some birds, like pigeons, have a small zone in their brain made of magnetite (magnetic mineral), just like a small compass. But other scientists think it's rather in their eyes that some birds have a system which indicates them where the magnetic north is...
Of course, (experienced) birds also use their knowledge of the landscape: they follow rivers, valleys or roads, or locate themselves with particular mountain peaks.
Other tracks are still to be explored. For example, it seems that some birds could find their way by following their sense of smell. ..."
http://www.educapoles.org/news/news_det ... _their_way

Posted here: viewtopic.php?p=613362#p613362
Migrating birds use a magnetic map to travel long distances
"Birds have an impressive ability to navigate. They can fly long distances, to places that they may never have visited before, sometimes returning home after months away.
Though there has been a lot of research in this area, scientists are still trying to understand exactly how they manage to find their intended destinations. ..."
http://theconversation.com/migrating-bi ... nces-82624

Posted here: viewtopic.php?p=613362#p613362
Vision-based magnetoreception
"One of the more complicated theories to explain avian migration involves bird species’ ability to detect the magnetic fields of the Earth, and subsequently follow those fields to their ultimate destination. This ability to use “invisible” waves was hard for some ornithologists to swallow, but it was proposed that some bird beaks contain magnetic particles that act as a compass. Recently, this theory has fallen out of fashion, replaced by the theory of vision-based magnetoreception.
The concept of vision-based magnetoreception means that birds can “see” magnetic fields and align themselves with the direction of the field they want to travel. If a bird is migrating south, it will align with a south-facing magnetic field and be on its way. Experiments in laboratories have actually generated artificial “magnetic south”, and birds moved in that direction. ..."
A Quantum Explanation?
"The last great mystery to vision-based magnetoreception is how this sort of magnetic field sensor can be present inside a bird’s retinal cells. One of the most recent theories suggests that quantum mechanics may provide the answer. For such a detector of strength AND direction, some mechanism would need to be in place to amplify the relatively weak magnetic effects of the Earth enough to be detected.
In quantum mechanics, a radical pair consists of two simultaneously created molecules, each with one electron of opposing, associated spin that makes these pairs highly sensitive to outside forces and magnetic fields.
When a specific light-sensitive protein found in the retinal cells of birds, cryptochrome, is exposed to certain wavelengths of green or blue light, it can organically create these radical pairs. Magnetoreception like this is the latest field of quantum biology, and one that is currently being studied around the world."
https://www.scienceabc.com/nature/how-m ... field.html

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Post by Anne7 » August 24th, 2019, 2:01 pm

Bird intelligence

Evolution of the neural basis of consciousness: a bird-mammal comparison.
Ann B. Butler, Paul R. Manger, B.I.B. Lindahl, and Peter Arhem
The main objective of this essay is to validate some of the principal, currently competing, mammalian consciousness-brain theories by comparing these theories with data on both cognitive abilities and brain organization in birds. Our argument is that, given that multiple complex cognitive functions are correlated with presumed consciousness in mammals, this correlation holds for birds as well. Thus, the neuroanatomical features of the forebrain common to both birds and mammals may be those that are crucial to the generation of both complex cognition and consciousness. The general conclusion is that most of the consciousness-brain theories appear to be valid for the avian brain. Even though some specific homologies are unresolved, most of the critical structures presumed necessary for consciousness in mammalian brains have clear homologues in avian brains. Furthermore, considering the fact that the reptile-bird brain transition shows more structural continuity than the stem amniote-mammalian transition, the line drawn at the origin of mammals for consciousness by several of the theorists seems questionable. An equally important point is that consciousness cannot be ruled out in the absence of complex cognition; it may in fact be the case that consciousness is a necessary prerequisite for complex cognition.
https://www.researchgate.net/publicatio ... comparison

The Perception of Self in Birds 2016
Sébastien Derégnaucourta, Dalila Bovet
The perception of self is an important topic in several disciplines such as ethology, behavioural ecology, psychology, developmental and cognitive neuroscience. Self-perception is investigated by experimentally exposing different species of animals to self-stimuli such as their own image, smell or vocalizations. Here we review more than one hundred studies using these methods in birds, a taxonomic group that exhibits a rich diversity regarding ecology and behaviour. Exposure to self-image is the main method for studying self-recognition, while exposing birds to their own smell is generally used for the investigation of homing or odor-based kin discrimination. Self-produced vocalizations - especially in oscine songbirds - are used as stimuli for understanding the mechanisms of vocal coding/decoding both at the neural and at the behavioural levels. With this review, we highlight the necessity to study the perception of self in animals cross-modally and to consider the role of experience and development, aspects that can be easily monitored in captive populations of birds.
https://www.researchgate.net/publicatio ... f_in_Birds

Reconsidering the evolution of brain, cognition, and behavior in birds and mammals
Romain Willemet
Despite decades of research, some of the most basic issues concerning the extraordinarily complex brains and behavior of birds and mammals, such as the factors responsible for the diversity of brain size and composition, are still unclear. This is partly due to a number of conceptual and methodological issues. Determining species and group differences in brain composition requires accounting for the presence of taxon-cerebrotypes and the use of precise statistical methods. The role of allometry in determining brain variables should be revised. In particular, bird and mammalian brains appear to have evolved in response to a variety of selective pressures influencing both brain size and composition. “Brain” and “cognition” are indeed meta-variables, made up of the variables that are ecologically relevant and evolutionarily selected. External indicators of species differences in cognition and behavior are limited by the complexity of these differences. Indeed, behavioral differences between species and individuals are caused by cognitive and affective components. Although intra-species variability forms the basis of species evolution, some of the mechanisms underlying individual differences in brain and behavior appear to differ from those between species. While many issues have persisted over the years because of a lack of appropriate data or methods to test them; several fallacies, particularly those related to the human brain, reflect scientists' preconceptions. The theoretical framework on the evolution of brain, cognition, and behavior in birds and mammals should be reconsidered with these biases in mind.
https://www.frontiersin.org/articles/10 ... 00396/full

Here's Why 'Birdbrain' Should Be a Compliment
https://news.nationalgeographic.com/201 ... alk/#close
Why is calling someone a birdbrain not the insult we thought it was?
For a long time, we thought that bird behaviour was just driven by instinct and that bird brains were so small and primitive they were only capable of the simplest mental processes. Calling someone a birdbrain meant there wasn’t much going on upstairs. But over the past several years, we’ve come to realize that birds are a lot smarter than we thought. Their brains are arranged differently from ours in what turn out to be very sophisticated ways. Birds can reason on a par with small children; craft tools as well as the big primate toolmakers, like chimps and orangutans; use language in ways we do; make complex navigational decisions; and remember where they put things, sometimes better than humans. They can also understand the mental state of another individual, which is one of the foundations of empathy. Some birds, like African grey parrots, have a remarkable facility with numbers. ...

Can birds count eggs in their nests?
Sensory mechanisms controlling avian clutch size have diversified into distinct types, according to the nature of the input that is used to disrupt the growth of ovarian follicles and hence halt egg‐laying. In an article on brood parasitism, Lyon (2003) claimed that female American Coots Fulica americana can reduce their clutch size on the basis of visual cues in response to eggs laid in their nests by other females; in this species, therefore, egg counting would be used to control clutch size. After a close examination of the physiological determination of clutch size in American Coots, I show that seven of 17 parasitized clutches were smaller than the range controlled through the mechanism using an input to disrupt follicular growth (7–10 eggs per clutch). My reanalysis suggests that American Coots are incapable of adjusting clutch size via counting and re‐asserts that a species that can count eggs has yet to be found among birds that rely upon their own body heat for incubation.
https://onlinelibrary.wiley.com/doi/abs ... /ibi.12328

The Wisdom Of Birds - An Illustrated History of Ornithology (book)
by Tim Birkhead
For thousands of years people have been fascinated by birds, and today that fascination is still growing. In 2007 bird-watching is one of the most popular pastimes, not just in America, but throughout the world, and the range of interest runs from the specialist to the beginner.
In The Wisdom of Birds, Birkhead takes the reader on a journey that not only tells us about the extraordinary lives of birds - from conception and egg, through territory and song, to migration and fully fledged breeder - but also shows how, over centuries, we have overcome superstition and untested 'truths' to know what we know, and how recent some of that knowledge is.
Conceived for a general audience, and illustrated throughout with more than 100 exquisitely beautiful illustrations, many of them rarely, if ever, seen before, The Wisdom of Birds is a book full of stories, knowledge and unexpected revelations.

The Genius of Birds (book)
by Jennifer Ackerman
An award-winning science writer tours the globe to reveal what makes birds capable of such extraordinary feats of mental prowess
Birds are astonishingly intelligent creatures. According to revolutionary new research, some birds rival primates and even humans in their remarkable forms of intelligence. In The Genius of Birds, acclaimed author Jennifer Ackerman explores their newly discovered brilliance and how it came about.
As she travels around the world to the most cutting-edge frontiers of research, Ackerman not only tells the story of the recently uncovered genius of birds but also delves deeply into the latest findings about the bird brain itself that are shifting our view of what it means to be intelligent. At once personal yet scientific, richly informative and beautifully written, The Genius of Birds celebrates the triumphs of these surprising and fiercely intelligent creatures.

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Post by Anne7 » August 24th, 2019, 3:33 pm

Bird Senses

In General

Bird Senses
Birds are fascinating aren't they? Many of us wonder what it would be like to be in the form of these feathered flying creatures. How well would we see, hear, taste and smell? How sensitive would we be to touch? Birds are fascinating aren't they? Many of us wonder what it would be like to be in the form of these feathered flying creatures. How well would we see, hear, taste and smell? How sensitive would we be to touch?
Since it is imperative for flight, birds rely heavily on sight for survival. In birds, the eyes are the largest organs in size relative to their bodies of all animals. Our eyes take up about 1% of the total weight of our heads. Most of the avian eye lies hidden by their skull and eyelids. Ostriches have eyes 2 inches in diameter, the largest eyes of any animal that lives on land. The eyes of large owls are about the size of ours, but account for one third of the weight of their heads. Starlings' eyes make up 15% of their head weight. In many birds, the eyes weigh more than the brain!

BIRD SENSES (article)
Tim Birkhead is a professor at the University of Sheffield, UK, where he teaches animal behaviour and the history of science. He is a fellow of the Royal Society of London and his research has taken him all over the world in the quest to understand the lives of birds.
"Of all the senses, the area I consider most fascinating is that of emotions. Do birds have emotions? Do they sense pain and pleasure? Some have argued that non-humans cannot experience such emotions as we do because they do not possess consciousness. This is a thorny issue, not least because consciousness is ill defined and extremely difficult to measure in any objective, scientific way. Nevertheless, there is now some evidence that birds do have emotions. Many, for example, maintain long-term pair bonds, and there are several anecdotal accounts of separated partners being reunited after a long period of absence, accompanied by behaviours – such as protracted greeting displays – that certainly imply they have an emotional bond."
https://liliec.be/resume/Nature/instant ... senses.pdf

BIRD SENSE - What it's Like to Be a Bird (book)
Tim Birkhead
What is going on inside the head of a nightingale as it sings, and how does its brain improvise? How do desert birds detect rain hundreds of kilometers away? How do birds navigate by using an innate magnetic compass? Tracing the history of how our knowledge about birds has grown, particularly through advances in technology over the past fifty years, Bird Sense tells captivating stories about how birds interact with one another and their environment.
Never before has there been a popular book about how intricately bird behavior is shaped by birds' senses. A lifetime spent studying birds has provided Tim Birkhead with a wealth of fieldwork experiences, insights, and a unique understanding of birds, all firmly grounded in science. No one who reads Bird Sense can fail to be dazzled by it.

Bird Senses

1. Smell (Olfaction)

Posted here: viewtopic.php?p=613362#p613362
Turns out birds can smell and taste after all
Recent studies show birds have a broad sensory palette, shooting earlier theories out of the water.

Small songbirds recently made a big contribution to human understanding of the sensory lives of birds. In a Spanish study of blue tits, birds related to our chickadee, researchers painted weasel scent around the entrance to a number of their nest boxes, and then watched to see if the birds showed signs of detecting it. The birds had been flying in and out to feed their youngsters, but began to hesitate after the scent of their chief predator was added to the entrance. Scientists concluded that the blue tits smelled the weasel musk, feared it was inside the box and had to overcome their fear in order to feed their brood.
If this seems merely intuitive, consider that for a very long time the scientific community has believed that birds, especially songbirds, have little to no sense of smell. Some poorly designed studies in the 1800s and 1900s seemed to prove that olfaction wasn’t important to birds.
So the belief grew that with the exception of carrion feeders like vultures, birds rely almost exclusively on their superb vision and hearing to make sense of their world.
And because birds have few taste buds, it was also thought that birds couldn’t taste what they eat.
I never quite accepted this assessment — there seemed to be no good reason why birds would lack these two vital senses. Besides, anyone who’s seen a Baltimore oriole gobble grape jelly or blue jays relishing peanuts just knows that these birds are tasting a favourite food.
But because researchers persisted in this belief, it led them to ignore what was in front of their very eyes. Increasingly, however, studies are showing that birds share every one of our five senses. ...
http://www.startribune.com/turns-out-bi ... 485946142/

Posted by Treia viewtopic.php?p=613332#p613332
Birds Have A Good Sense Of Smell
Sight and hearing are the most important senses for birds - this is at least the received wisdom. By studying bird DNA, however, researchers at the Max Planck Institute for Ornithology, along with a colleague at the Cawthron Institute in New Zealand, have now provided genetic evidence that many bird species have a well-developed sense of smell (Proceedings of the Royal Society B, 16.07.2008).
The sense of smell might indeed be as important to birds as it is to fish or even mammals. This is the main conclusion of a study by Silke Steiger (Max Planck Institute for Ornithology) and her colleagues. The sense of smell in birds was, until quite recently, thought to be poorly developed.
https://www.sciencedaily.com/releases/2 ... 111421.htm

The underestimated role of olfaction in avian reproduction ?
Jacques Balthazart and Mélanie Taziaux
Until the second half of the 20th century, it was broadly accepted that most birds are microsmatic if not anosmic and unable to detect and use olfactory information. Exceptions were eventually conceded for species like procellariiforms, vultures or kiwis that detect their food at least in part based on olfactory signals. During the past 20–30 years, many publications have appeared indicating that this view is definitely erroneous. We briefly review here anatomical, electrophysiological and behavioral data demonstrating that birds in general possess a functional olfactory system and are able to use olfactory information in a variety of ethological contexts, including reproduction. Recent work also indicates that brain activation induced by sexual interactions with a female is significantly affected by olfactory deprivation in Japanese quail. Brain activation was measured via immunocytochemical detection of the protein product of the immediate early gene c-fos. Changes observed concerned two brain areas that play a key role in the control of male sexual behavior, the medial preoptic nucleus and the bed nucleus of the stria terminalis therefore suggesting a potential role of olfaction in the control of reproduction. The widespread idea that birds are anosmic or microsmatic is thus not supported by the available experimental data and presumably originates in our anthropomorphic view that leads us to think that birds do not smell because they have a rigid beak and nostrils and do not obviously sniff. Experimental analysis of this phenomenon is thus warranted and should lead to a significant change in our understanding of avian biology.

Birds Can Smell, and One Scientist is Leading the Charge to Prove It
By Nancy Averett
January-February 2014

Gabrielle Nevitt’s supply list for her first Antarctic research cruise in 1991 contained some decidedly odd items. The huge kites and vats of fishy smelling liquid wouldn’t be a problem, the macho National Science Foundation contractor told her. Then she asked for hundreds of boxes of super-absorbent tampons. “He just kind of stammered,” recalls Nevitt a petite brunette who was then a 31-year-old zoology post-doc at Cornell University. “Then he said, ‘Uh, I don’t think I can get those for you, ma’am.’ ” So Nevitt lugged them onboard herself and set to work. She was hoping to lure albatrosses and petrels from the open sea with the scent of dinner, like a street-food vendor might entice passersby with a hot pretzel. She dipped the tampons in pungent compounds found in marine fish and small crustaceans called krill, and painstakingly attached the briny bait to parachute-like kites that she let fly off the rear deck. Then she waited.
It was an outlandish experiment, and not just because of the tampons. For more than a century nearly everyone believed that the sense of smell was poorly developed or nonexistent in most birds. So no one had ever fully investigated to what extent tube-nosed procellariiformes—petrels, albatrosses, and shearwaters—use their olfactory anatomy to pinpoint prey in the vast, featureless ocean. ...
https://www.audubon.org/magazine/januar ... -scientist

Diversity in olfactory bulb size in birds reflects allometry, ecology, and phylogeny
Jeremy R. Corfield, Kasandra Price, Andrew N. Iwaniuk, Cristian Gutierrez-Ibañez, Tim Birkhead and Douglas R. Wylie
Front. Neuroanat., 29 July 2015

The importance of olfaction to bird ecology and behavior has largely been underplayed. In fact, early ornithologists debated if birds had a sense of smell at all. However, recent interest in avian olfaction is demonstrating that birds have a fully functional olfactory system and some species rely heavily on their sense of smell for many tasks. Birds use olfaction in a wide range of contexts that parallel that of mammals and other vertebrates, including: foraging, predator avoidance, advertisement and mate selection, to discriminate conspecifics, consubspecifics, and sexes and even for territorial scent marking. To support these behaviors, sensitivities to odors in birds are comparable to that of some mammals.
https://www.frontiersin.org/articles/10 ... 00102/full

Birds and Dogs: Toward a Comparative Perspective on Odor Use and Detection
Paola Prada and Kenneth G. Furton
Front. Vet. Sci., 14 August 2018

While canines are generally considered the gold standard for olfactory detection in many situations other animals provide alternatives and offer a unique opportunity to compare biological detection capabilities. Critical components in successfully studying biological detectors is not only understanding their anatomical evidence for olfaction, but also, understanding the life history of the species to better direct the potential of an olfactory task. Here, a brief overview is provided presenting a comparative viewpoint on the use of odors by birds and canines over a range of unique detection scenarios. Similar to canines, birds use olfactory information in various natural oriented contexts where odors are dispersed over a widespread spatial range. Comparing these two distinctive animal models, and current trends in physiological and behavioral assessments may open the door for novel uses of birds as biological sensors in forensic applications.
https://www.frontiersin.org/articles/10 ... 00188/full

MOXD2, a Gene Possibly Associated with Olfaction, Is Frequently Inactivated in Birds
Chul Jun Goh, Dongjin Choi, Dong-Bin Park, Hyein Kim, Yoonsoo Hahn
Published: April 13, 2016

Vertebrate MOXD2 encodes a monooxygenase DBH-like 2 protein that could be involved in neurotransmitter metabolism, potentially during olfactory transduction. Loss of MOXD2 in apes and whales has been proposed to be associated with evolution of olfaction in these clades. We analyzed 57 bird genomes to identify MOXD2 sequences and found frequent loss of MOXD2 in 38 birds. Among the 57 birds, 19 species appeared to have an intact MOXD2 that encoded a full-length protein; 32 birds had a gene with open reading frame-disrupting point mutations and/or exon deletions; and the remaining 6 species did not show any MOXD2 sequence, suggesting a whole-gene deletion. Notably, among 10 passerine birds examined, 9 species shared a common genomic deletion that spanned several exons, implying the gene loss occurred in a common ancestor of these birds. However, 2 closely related penguin species, each of which had an inactive MOXD2, did not share any mutation, suggesting an independent loss after their divergence. Distribution of the 38 birds without an intact MOXD2 in the bird phylogenetic tree clearly indicates that MOXD2 loss is widespread and independent in bird lineages. We propose that widespread MOXD2 loss in some bird lineages may be implicated in the evolution of olfactory perception in these birds.
https://journals.plos.org/plosone/artic ... ne.0152431

Olfactory Communication via Microbiota: What Is Known in Birds?
Öncü Maraci, OrcID, Kathrin Engel, and Barbara A. Caspers
Genes 2018, 9(8), 387

Animal bodies harbour a complex and diverse community of microorganisms and accumulating evidence has revealed that microbes can influence the hosts’ behaviour, for example by altering body odours. Microbial communities produce odorant molecules as metabolic by-products and thereby modulate the biochemical signalling profiles of their animal hosts. As the diversity and the relative abundance of microbial species are influenced by several factors including host-specific factors, environmental factors and social interactions, there are substantial individual variations in the composition of microbial communities. In turn, the variations in microbial communities would consequently affect social and communicative behaviour by influencing recognition cues of the hosts. Therefore, microbiota studies have a great potential to expand our understanding of recognition of conspecifics, group members and kin. In this review, we aim to summarize existing knowledge of the factors influencing the microbial communities and the effect of microbiota on olfactory cue production and social and communicative behaviour. We concentrate on avian taxa, yet we also include recent research performed on non-avian species when necessary.
Figure 1. Possible factors involved in shaping microbiota-based communication.

Olfaction in Chicken (Gallus gallus): A Neglected Mode of Social Communication?
E. Tobias Krause, Lars Schraderand Barbara A. Caspers
Front. Ecol. Evol., 09 August 2016

Avian olfaction has been neglected for a long time, although pioneering work has been conducted from the 1960th on. However, much of this research focused on odor perception in general or on the use of olfactory cues in non-social contexts, e.g., for navigation or foraging . In addition, this research focused on few avian taxa, in which the olfactory sense was regarded to be important due to large relative olfactory bulbs. These taxa included, for example, the kiwi (Apteryx australia), which has a relative olfactory bulb size of 34% (ratio of the bulb to the hemisphere), the Procellariiformes, i.e., tube-nosed marine birds, with a mean ratio of 29%, and few other species and taxa.
https://www.frontiersin.org/articles/10 ... 00094/full

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Post by Anne7 » August 24th, 2019, 5:27 pm

Bird Senses

1. Smell (olfaction)
The Role of Olfaction in Avian Navigation

True navigation in migrating gulls requires intact olfactory nerves
Martin Wikelski, Elena Arriero, Anna Gagliardo, Richard A. Holland, Markku J. Huttunen, Risto Juvaste, Inge Mueller, Grigori Tertitski, Kasper Thorup, Martin Wild, Markku Alanko, Franz Bairlein, Alexander Cherenkov, Alison Cameron, Reinhard Flatz, Juhani Hannila, Ommo Hüppop, Markku Kangasniemi, Bart Kranstauber, Maija-Liisa Penttinen, Kamran Safi, Vladimir Semashko, Heidi Schmid & Ralf Wistbacka
Scientific Reports volume 5, Article number: 17061 (2015)

During migratory journeys, birds may become displaced from their normal migratory route. Experimental evidence has shown that adult birds can correct for such displacements and return to their goal. However, the nature of the cues used by migratory birds to perform long distance navigation is still debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to < 5°N) to sensory manipulation, to determine the sensory systems required for navigation. We translocated birds westward (1080 km) or eastward (885 km) to simulate natural navigational challenges. When translocated westwards and outside their migratory corridor birds with olfactory nerve section kept a clear directional preference (southerly) but were unable to compensate for the displacement, while intact birds and gulls with the ophthalmic branch of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances.

Posted by Treia https://www.looduskalender.ee/forum/vie ... 32#p613332
Sense of smell is key factor in bird navigation
How do birds navigate over long distances? This complex question has been the subject of debate and controversy among scientists for decades, with Earth's magnetic field and the bird's own sense of smell among the factors said to play a part.
Now, researchers from the universities of Oxford, Barcelona and Pisa have shown in a new experiment that olfaction – or sense of smell – is almost certainly a key factor in long-distance oceanic navigation, eliminating previous misgivings about this hypothesis.
http://www.ox.ac.uk/news/2017-08-29-sen ... navigation

Olfactory navigation versus olfactory activation: a controversy revisited
Charles Walcott, Wolfgang Wiltschko, Roswitha Wiltschko, Günther K. H. Zupanc
Journal of Comparative Physiology A; August 2018, Volume 204, Issue 8, pp 703–706

In the early 1970s, Floriano Papi and colleagues proposed the olfactory-navigation hypothesis, which explains the homing ability of pigeons by the existence of an odor-based map acquired through learning. This notion, although supported by some observations, has also generated considerable controversy since its inception. As an alternative, Paulo Jorge and colleagues formulated in 2009 the olfactory-activation hypothesis, which states that atmospheric odorants do not provide navigational information but, instead, activate a non-olfactory path integration system. However, this hypothesis is challenged by an investigation authored by Anna Gagliardo and colleagues and published in the current issue of the Journal of Comparative Physiology A. In this editorial, the significance of the findings of this study is assessed in the broader context of the role of olfaction in avian navigation and homing, and experiments are suggested that might help to finally resolve the olfactory-navigation versus olfactory-activation controversy.
https://link.springer.com/article/10.10 ... 018-1273-1

Data from: Olfaction and topography, but not magnetic cues, control navigation in a pelagic seabird: displacements with shearwaters in the Mediterranean Sea
Pollonara E, Luschi P, Guilford T, Wikelski M, Bonadonna F, Gagliardo A
(2015) Olfaction and topography, but not magnetic cues, control navigation in a pelagic seabird: displacements with shearwaters in the Mediterranean Sea. Scientific Reports. doi:10.1038/srep16486

Pelagic seabirds wander the open oceans then return accurately to their habitual nest-sites. We investigated the effects of sensory manipulation on oceanic navigation in Scopoli’s shearwaters (Calonectris diomedea) breeding at Pianosa island (Italy), by displacing them 400 km from their colony and tracking them. A recent experiment on Atlantic shearwaters (Cory’s shearwater, Calonectris borealis) breeding in the Azores indicated a crucial role of olfaction over the open ocean, but left open the question of whether birds might navigate by topographical landmark cues when available. Our experiment was conducted in the Mediterranean sea, where the availability of topographical cues may provide an alternative navigational mechanism for homing. Magnetically disturbed shearwaters and control birds oriented homeward even when the coast was not visible and rapidly homed. Anosmic shearwaters oriented in a direction significantly different from the home direction when in open sea. After having approached a coastline their flight path changed from convoluted to homeward oriented, so that most of them eventually reached home. Beside confirming that magnetic cues appear unimportant for oceanic navigation by seabirds, our results support the crucial role of olfactory cues for birds’ navigation and reveal that anosmic shearwaters are able to home eventually by following coastal features.
https://www.datarepository.movebank.org ... 5/move.457

Olfactory navigation of pigeons represented by aerosol dispersion modeling
Handler Miriam
2018, Master of Science, Ohio State University, Environmental Science

The influence of anosmia on pigeon (Columba livia) navigation has been proven significant by biological and physical experiments conducted over decades. Although contested by competing hypotheses, navigation by olfaction has become the most modern and accepted hypothesis explaining homing behavior in pigeons. Pigeons possess the ability to store olfactory information in their memory for later recollection when displaced from home. Exactly how pigeons employ this remarkable skill has been cause for investigation. To understand how this mechanism works, a virtual olfactory map was generated by tracing air parcel trajectories 24 hours back in time to model their origin. This was repeated over the entire free-flying period of inexperienced pigeons kept at a field station in Arnino within Pisa, Italy until controlled release at some point later in time. Given the relationship between wind direction and the movement of air parcels, the origin locations of the virtual air-parcel trajectories were thus correlated with the wind direction blowing at the home loft at the time of the arrival of the air parcel. We hypothesize that by associating the wind direction with smell, it brings the pigeons to form a mental olfactory map. To quantify the strength of the olfactory map, we experimentally released birds under two treatments. Pigeons were either untreated (control group - C) or made anosmic, i.e., unable to smell (treatment group - ZnPA). Trajectories back toward the loft were recorded using GPS trackers mounted on the birds. Three indices quantified the density of different aspects of the mental olfactory map: Representation (RI), Uniqueness (UI), and Orientation Consistency (OCI), were created and compared to pigeon homing indices: Homing Efficiency Index (HEI) and Homing Component (HC), and to quantitative characteristics of the pigeon movement behaviors. A significant and positively-sloping relationship was found between C-group pigeons’ HEI and RI, whereas no significant relationship was found between any of the olfactory map and homing indices for ZnPA pigeons. Additional track characteristics were related to multiple olfactory map indices for both C and ZnPA pigeons. In addition to navigation via olfaction, the utilization of land cover class was explored by annotating the tracks of C and ZnPA pigeons with remote sensing data of land cover. The distributions of land cover classes among the tracks of C and ZnPA birds were compared to one another in addition to comparing their annotated tracks to the distribution of land cover classes in the available background. All comparisons displayed significantly different distributions, indicating that the pigeons had some preference with respect to land cover, helping to explain some of the unexpected relationships between ZnPA pigeon track behaviors and olfactory map indices that necessarily pass through land cover types with associated odors. Overall, the significant relationships between olfactory map indices and homing efficiency in untreated birds and the lack of such relationships in treated birds indicate that an olfactory map is created by relating wind directions with smells during the free-flying period. Our findings help shed light on the method by which pigeons apply smells to find their way.
https://etd.ohiolink.edu/!etd.send_file ... ion=inline

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Post by Anne7 » August 24th, 2019, 5:55 pm

Bird Senses

2. Sight (vision)


The Avian Eye and Vision
by Mr Gordon Ramel
A bird's eye is very similar in its basic structure to a human eye. Though with certain modifications and differences.
The eyes make up a much larger percentage of the weight of the head in birds than in man, i.e. 15% for a common Starling but only 1% for man. This is partly because a bird's eyes are larger relative to its skull than a human's and partly because the skull is lighter, i.e. no heavy jaw bone and teeth.
A bird's eye is very tightly fitted into its skull and it is capable of very little movement, therefore birds can often be seen moving their heads in order to change their visual relationship to something. In most birds the eyes are placed much nearer the sides of the head than in humans. This gives the bird a greater overall field of view, but greatly reduces its binocular vision (the area in which both eyes can see an object).
In man, binocular vision is about 140 degrees out of a total of about 180 degrees. In a pigeon though the binocular area is only 20-30 degrees out of a total field of vision of 300-340 degrees. In many raptors and owls the situation is different. In these birds, as in many insectivorous birds, binocular vision, important in making judgements of distance, is more necessary and so these birds have their eyes more towards the front of their heads. This is most evident in owls where the total field of view is reduced to about 110 degrees with a binocular vision of 70 degrees. This is why owls turn their heads to watch you walk past. An owl can turn its head through over 200 degrees but cannot move its eyes in its head at all.

The most important parts of the bird's eye are:
The Eyelids - birds have 3 eyelids; one upper and one lower eyelid, of which the lower is more moveable, and a nictitating membrane. This nictitating membrane is between the other two eyelids and the cornea and has its own lubricating duct equivalent to our tear duct. It is used in cleaning and protecting the eye.
The Cornea - this is the protective covering on the outer surface of the eye.
The Anterior Chamber - this is the space immediately behind the cornea and leading to the iris and the lens. It is filled with a fluid called the aqueous humor.
The Iris - this is a muscularly operated diaphragm which controls the amount of light entering the eye. It is coloured and it is this that gives the eye its colour. At the centre of the iris is the variable hole through which the light actually passes on its way into the eye, this is called the pupil.
The Lens - this is a transparent convex or 'lens' shaped body with a harder outer layer and a softer inner layer. It serves to focus the light on the retina. Its shape can be altered by means of the ciliary muscles which are attached to the eye by means of the zonular fibres.
The Posterior Chamber - this is the bulk of the eye and is the space behind the lens and between the lens and the retina. It is filled with a clear jelly-like substance called the vitreous humor.
The Retina - this is the inner light receptive part of the eye. It is covered in special 'photoreceptive' cells called rods and cones. Towards the centre of the retina is an area called the fovea centralis which has a greater density of 'receptors' or rods and cones. This is the area of greatest visual acuity, i.e. sharpest, clearest detection of objects. The number of receptors per square millimetre determines the degree of visual acuity an animal has, the more receptors the higher its ability to distinguish individual objects at a distance. In some birds such as hawks, kingfishers and swallows, the eye has 2 fovea, one for sideways viewing and one for forward viewing. In many raptors, the fovea centralis has far more rods and cones than in humans and it is this which allows these birds their spectacular long-distance vision. We have about 200 000 receptors per mm2, sparrows, however, have about 400 000 while a Buzzard has an incredible 1 000 000 receptors per mm2. The fovea itself can also be lens-shaped increasing the effective number of receptors per mm2 yet again. Buzzards, for instance, have distance vision 6 to 8 times better than ours, part of this is a result of the lens-shaped central fovea which acts something like a x2 magnifying lens.
The Pecter - this is a poorly understood body. It is strongly supplied with blood vessels and is thought to help keep the retina well supplied with nutrients.
The Optic Nerve - this is a bundle of nerve fibres which carry messages from the eye to the relevant parts of the brain and vice-versa. Like us, birds have a small blind spot where the optic nerve meets the retina.
The Sclera - a tough collagen fibre layer which surrounds the whole inner part of the eye (that part not covered by the cornea), it supports and protects the eye as a whole.

By Jimfbleak at English Wikipedia, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4497634
There are two sorts of light receptors in the bird's eye. They are called 'rods' and 'cones'. Rods are better for night vision because they are sensitive to small quantities of light. However as it is the cones that allow us to distinguish between different colours of light they are more important to colour orientated animals such as birds. Also, there can be as many as 150 rods connected to a single nerve cell, this increases its sensitivity but reduces its definition, i.e. things look blurry. Cones can be as few as one or two per nerve cell, this works the opposite way making them less sensitive but more accurate for detail. Which is good during the daylight. Cones come in different flavours depending on which pigment they contain, different pigments detect different colours. Birds have 5 pigments (we only have 3) this gives them greater sensitivity to certain colours allowing them to see more different shades of some colours such as red than we can. In birds also the cones have special oil droplets on them which help filter the light, making the cones more sensitive to smaller ranges of colour. As they have five different sorts of oil filters the eyes of birds can often see a far more subtle world than we can. Sea birds such as the Procellariformes use red oil filters to cut out the blue light scattered up from the sea. This makes it easier for them to discern small objects floating on or near the surface.

What Birds See
By Timothy H. Goldsmith
We humans customarily assume that our visual system sits atop a pinnacle of evolutionary success. It enables us to appreciate space in three dimensions, to detect objects from a distance and to move about safely. We are exquisitely able to recognize other individuals and to read their emotions from mere glimpses of their faces. In fact, we are such visual animals that we have difficulty imagining the sensory worlds of creatures whose capacities extend to other realms— a night-hunting bat, for example, that finds small insects by listening to the echoes of its own high-pitched call.
Our knowledge of colour vision is, quite naturally, based primarily on what humans see: researchers can easily perform experiments on cooperative human subjects to discover, say, what mixtures of colours look the same or different. Although scientists have obtained supporting information from a variety of other species by recording the firing of neurons, we remained unaware until the early 1970s that many vertebrates, mostly animals other than mammals, see colours in a part of the spectrum that is invisible to humans: the near-ultraviolet.
https://web.archive.org/web/20110410051 ... 090424.pdf

Avian Vision: A Review of Form and Function with Special Consideration to Birds of Prey
Michael P. Jones, Kenneth E. Pierce and Daniel Ward
More so than any other terrestrial vertebrate, birds rely most heavily on their ability to assess their visual environment. High visual acuity is not only necessary to find and acquire food, but also to navigate surroundings, to identify conspecifics and potential mates, and to quickly identify and escape from predators. This article aims to help the reader understand how birds, particularly birds of prey, see by reviewing pertinent anatomy and physiology of the eye, colour vision, visual fields, visual acuity, accommodation, and flicker-fusion frequency. For more information on specific disease conditions of the avian eye, the reader is encouraged to review any number of avian medical and surgical texts.
https://web.archive.org/web/20081217154 ... vision.pdf

How do birds look at their world? A novel avian visual fixation strategy
Shannon R. Butler, Jennifer J. Templeton, Esteban Fernández-Juricic
Behavioral Ecology and Sociobiology; March 2018, 72:38

A central assumption in behavioral research is that the observer knows where an animal is looking; however, establishing when an animal is gazing (i.e., visually fixating on an object) has been challenging in species with laterally placed eyes. We quantitatively tested three fixation strategies proposed in the literature for birds, using European starlings (Sturnus vulgaris). We did not find strong support for any of the three strategies, despite high statistical a priori power (93%). However, we did observe a new visual fixation strategy that we labeled monocular alternating fixation. In this strategy, starlings moved their heads to make multiple fixations with a single eye before switching to the other eye and repeating the same process. Additionally, we established that individuals favored using the left over the right eye, supporting that laterality in starlings is left-eye dominant. The newly observed fixation strategy may be associated with the high level of intra-retinal variation (density of photoreceptors, overall sensitivity of visual pigments, etc.) in the starling retina. From a functional perspective, this monocular alternating fixation strategy may be beneficial to integrate the different types of information gathered by the different portions of each retina more quickly. We discuss the implications of our results for designing and interpreting behavioral experiments that require an understanding of where a bird is looking.
Significance statement:
This is the first study to quantitatively test three hypotheses in the literature about how animals with laterally placed eyes look at objects. We found that there was not strong support for any of these three strategies, but found support for a newly described strategy for birds to look at objects (i.e., multiple looks with a single eye before switching to the other eye).

Avian UV vision enhances leaf surface contrasts in forest environments
Cynthia Tedore & Dan-Eric Nilsson

UV vision is prevalent, but we know little about its utility in common general tasks, as in resolving habitat structure. Here we visualize vegetated habitats using a multispectral camera with channels mimicking bird photoreceptor sensitivities across the UV-visible spectrum. We find that the contrast between upper and lower leaf surfaces is higher in a UV channel than in any visible channel, and that this makes leaf position and orientation stand out clearly. This was unexpected since both leaf surfaces reflect similarly small proportions (1–2%) of incident UV light. The strong UV-contrast can be explained by downwelling light being brighter than upwelling, and leaves transmitting < 0.06% of incident UV light. We also find that mirror-like specular reflections of the sky and overlying canopy, from the waxy leaf cuticle, often dwarf diffuse reflections. Specular reflections shift leaf color, such that maximum leaf-contrast is seen at short UV wavelengths under open canopies, and at long UV wavelengths under closed canopies.
https://www.nature.com/articles/s41467- ... rigin=ppub

Ultraviolet Vision in Birds
Innes C.Cuthill, Julian C.Partridge, Andrew T.D.Bennett, Stuart C.Church, Nathan S.Hart, SarahHunt
Advances in the Study of Behavior; Volume 29, 2000, Pages 159-214

Publisher Summary
Birds can see ultraviolet (UV) light because, unlike humans, their lenses and other ocular media transmit UV, and they possess a class of photoreceptor, which is maximally sensitive to violet or UV light, depending on the species. Birds have a tetrachromatic color space, as compared to the trichromacy of humans. Birds, along with some reptiles and fish, also possess double cones in large numbers and a cone class. This chapter discusses a range of behavioral experiments, from several species, which show that UV information is utilized in behavioral decisions, notably in foraging and signaling. Removal of UV wavelengths affects mate choice even in species that are colorful to humans. These studies emphasize that avian and human color perceptions are different and that the use of human color standards, and even artificial lighting, may produce misleading results. However, genuinely objective measures of color are available, as are, importantly, models for mapping the measured spectra into an avian color space.
https://www.sciencedirect.com/science/a ... 5408601059

COPING WITH LIGHT REFRACTION at the air/water interface.

Stationary underwater prey missed by reef herons, Egretta gularis:
head position and light refraction at the moment of strike

Gadi Katzir, Arnon Lotem and Nathan Intrator
Summary: This paper attempts to verify the importance of spatial positioning of the eyes of reef herons Egretta gularis schistacea, when coping with light refraction at the air-water interface. The herons' striking of prey, while their approach angle was restricted, was observed. (a) The herons' capture success in the restricted situation was markedly lower than in the unrestricted situation. (b) The points of strike (STR) in unsuccessful strikes differed from those of successful strikes, and from those of the unrestricted situation. (c) The larger the difference between the observed and the predicted ratio of prey depth to apparent prey depth, the higher the probability of missing a prey. These results support predictions of a model presented elsewhere (Katzir and Intrator 1987) that a heron will attempt to reach spatial positions at which prey's real depth and apparent depth are linearly correlated.
https://web.archive.org/web/20160304043 ... ysiolA.pdf

Capture of submerged prey by little egrets, Egretta garzetta garzetta:
strike depth, strike angle and the problem of light refraction

Abstract: How little egrets catch submerged prey was observed in the field. The proportion of successful strikes was measured relative to the angle and depth of the strike and the water level in the pond. Prey capture success was significantly related to strike angle, being highest at the most acute angles. Strike depth had no effect on capture success. Strikes were more successful in shallow streams than in full or partly drained ponds. Adult breeding birds were as successful as non-breeders and juveniles, but performed deeper strikes more often. There was also significant variation between individuals in capture success. Light refraction had no apparent effect on the egrets' capture success.
https://www.tau.ac.il/~lotem/Lotem%20et ... mBehav.pdf

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Post by Anne7 » August 24th, 2019, 6:29 pm

Bird Senses

3. Hearing

Hearing is believing: Birds learn fear
Christopher B. Sturdy, Darren S. Proppe
Learning & Behavior; September 2016, Volume 44, Issue 3, pp 205–206

Although it is known that animals attend to the vocalizations of others (referred to as eavesdropping), what has been missing, or at least left experimentally unproven, until now is whether animals can learn new associations between a signal and a threat. Here Magrath and colleagues (Current Biology, 25(15), 2047–2050, 2015) have for the first time conducted a field experiment that demonstrates just this: superb fairy-wrens learned to associate a novel vocalization with a predator.
https://link.springer.com/article/10.37 ... 015-0207-9

Do we hear what birds hear in birdsong?
Robert J. Dooling, Nora H. Prior
Peter Marler's fascination with richness of birdsong included the notion that birds attended to some acoustic features of birdsong, likely in the time domain, which were inaccessible to human listeners. While a considerable amount is known about hearing and vocal communication in birds, how exactly birds perceive their auditory world still remains somewhat of a mystery. For sure, field and laboratory studies suggest that birds hear the spectral, gross temporal features (i.e. envelope) and perhaps syntax of birdsong much like we do. However, there is also ample anecdotal evidence that birds are consistently more sensitive than humans to at least some aspects of their song. Here we review several psychophysical studies supporting Marler's intuitions that birds have both an exquisite sensitivity to temporal fine structure and may be able to focus their auditory attention on critical acoustic details of their vocalizations. Zebra finches, Taeniopygia guttata, particularly, seem to be extremely sensitive to temporal fine structure in both synthetic stimuli and natural vocalizations. This finding, together with recent research highlighting the complexity of zebra finch vocalizations across contexts, raises interesting questions about what information zebra finches may be communicating in temporal fine structure. Together these findings show there is an acoustic richness in bird vocalizations that is available to birds but likely out of reach for human listeners. Depending on the universality of these findings, it raises questions about how we approach the study of birdsong and whether potentially significant information is routinely being encoded in the temporal fine structure of avian vocal signals.

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Post by Anne7 » August 26th, 2019, 12:02 pm

Bird Senses

4. Touch (tactition)

Posted here: viewtopic.php?p=578896#p578896
Vibrations and Touch in Birds
"Some birds also have large numbers of vibration sensors called Herbot's corpuscles located in their legs. These allow them to detect the approach of other birds or predators along both the ground and on the limbs of trees. Herbot's corpuscles have also come to play a role in the nuptial displays of certain species of grouse. This ability to detect very faint vibrations has also been suggested as a reason why birds seem to know when an earthquake is about to happen before we humans have any idea about it."

A comparative analysis of the organization of the sensory units in the beak of duck and quail 2017
Soha A Soliman, Fatma A Madkour
The current study compared organization of the sensory receptors in duck and quail beak. Samples of beak were collected and processed for paraffin and semithin sectioning and SEM. The typical structure of the sensory receptors was detected by different histochemical stains. The topographical distribution of various types of mechanoreceptors was different within the two species. Higher proportions of sensory receptors were evaluated as Herbst and Grandry corpuscles in the bill tip organ, Herbst in the aboral surface of the lateral edge of the cranial part and in the middle site of the oral mucosa of the middle and caudal parts of duck beak. Prevalence of the sensory receptors in quail was also estimated; Merkel receptors in the tip, Ruffini corpuscles in the middle site of the oral mucosa of the cranial and caudal parts. Analysis of the predominant proportions of the sensory receptors in the different divisions of duck and quail beak outlined the functional map of the beak in both species. Duck beak was mostly responding to vibration stimuli particularly the cranial and the caudal part, while quail beak was more sensitive stretching, especially in the cranial portion. In duck beak, the functional map was organized as stretching sensors in the cranial part, pressure sensors in the cranial and the middle parts, velocity sensors in the cranial and caudal parts. While in quail beak, the functional map was organized as the vibration and stretching in the cranial part, pressure in the tip and the cranial portions.
https://www.oatext.com/a-comparative-an ... -quail.php

Smart beaks: non-visual senses in birds
Carla du Toit
Most birds, like most people, have excellent vision. This is part of what makes birds such an appealing group to study. However birds navigate their world using different senses as well. In this project, we investigate the non-visual senses of birds with a focus on tactile senses in their beaks. The main theme of the project is to understand the links between bill-tip anatomy and foraging ecology of the three species of southern African ibises: Hadeda Bostrychia hagedash, Sacred Ibis Threskiornis aethiopicus and Glossy Ibis Plegadis falcinellus. These species all have a honeycomb pattern of pitting in the bones of the bill tips which suggests they should be able to forage using the sixth sense “remote touch”: detection of small vibrations made by prey as they burrow or swim through the foraging substrate (soil, mud or water)
http://www.fitzpatrick.uct.ac.za/fitz/r ... mart_beaks

The evolution of the sense of touch in birds: the role of the avian tactile bristle
Mariane G. Delaunay, Robyn A. Grant, 2016
The sense of touch was a cornerstone in mammalian evolution. It is one of the most specialised sensory systems, driving brain complexity and behavioural flexibility. Some bird species also possess tactile sensors that are analogous to mammalian whiskers; however, they have been largely overlooked by researchers. These sensors take the form of rictal bristles, a type of facial feather present notably in the Caprimulgiformes order (Nightjars and related species). This study is the first step in characterising bristle morphology and anatomy in birds, focussing especially on the Caprimulgiformes. 183 specimens were measured from 61 nightjar species at Tring Natural History Museum and it was found that bristle features (thickness, branching, and length) varied greatly between species, with no clear evolutionary pattern occurring within the nightjar phylogeny. Anatomical work on two closely related African nightjars (Pennant-winged and Fiery-necked) showed large variation within the rictal bristle follicle. The Pennant-winged nightjar had intrinsic muscle fibers around bristle follicles, whereas the Fiery-necked nightjar had intrinsic collagen fibers and mechanoreceptors. Despite the difference, the presence of intrinsic fibers suggests that the bristles may well be moveable, and the mechanoreceptors reveal their role in touch sensing. The next step will be to characterise the neuroanatomy to assess whether the brain structure and connections also varies greatly between these two related species. Future studies, within the PhD, will expand this work further, by firstly investigating other bird groups to see how and why rictal bristles might be present in certain species; and secondly defining bristle-use during foraging.
http://www.sciengsymp.co.uk/2016/the-ev ... e-bristle/

Tactile senses and foraging in birds, with emphasis on kiwi
Susan Jane Cunningham, 2010
Probe-foraging birds must often rely on senses other than vision for prey-detection. One such sense is ‘remote touch’: the detection of vibration and pressure cues from prey within the substrate. Remote touch is mediated by the ‘scolopacid-type bill-tip organ’, which consists of a honeycomb of sensory pits in the bill-tip, containing clusters of mechanoreceptors. This organ was originally described in the neognathous shorebird family Scolopacidae, but was recently also discovered in paleognathous kiwi (Apterygidae): an example of convergent/parallel evolution. My aim was to discover how widespread this organ is among birds, compare its anatomy and function in foraging between kiwi and other probe-foraging birds and elucidate in detail the foraging behaviours and senses used by free-living kiwi. Within the thesis I compare the bill-tip organs of kiwi and shorebirds using material from the brown kiwi (Apterygidae: Apteryx mantelli) and bar-tailed godwit (Scolopacidae: Limosa lapponica). I provide the first description of the organ in a third family of birds, the ibises (Threskiornithidae), and give evidence that it may exist in simplified form in a fourth family, Rallidae. The Scolopacidae, Apterygidae, Threskiornithidae and Rallidae are widely separated on the avian phylogenetic tree. This suggests that the evolution of the scolopacid-type bill-tip organ and associated sense is favoured by a probe-foraging lifestyle. Foraging trials confirm the bill-tip organs of brown kiwi and Madagascar crested ibises (Lophotibis cristata urschi) are functional for remote touch. The ibises rely solely on remote touch to find buried prey, whereas brown kiwi use the sense in conjunction with olfaction. Free-living brown kiwi display no obviously visually-guided behaviours, instead using hearing (head-lifting in response to noises audible to the observer), olfaction (odour sensing behaviour, ‘sniffing,’ in the direction of these sounds) and touch. Kiwi tap ahead with their bill-tip when walking and move their facial bristles forward when foraging, forming a ‘net’ on the ground. The bristle follicles in kiwi (and some other insectivorous bird species) are innervated with Herbst corpuscles, suggesting tactile function. Female kiwi probe on average 30% deeper than males and juveniles, but there are no other differences in foraging behaviour between the sexes.
https://pdfs.semanticscholar.org/88aa/f ... fccdac.pdf

A Cross-Species Analysis Reveals a General Role for Piezo2 in Mechanosensory Specialization of Trigeminal Ganglia from Tactile Specialist Birds
Eve R.Schneider, Evan O.Anderson, Viktor V. Feketa, Marco Mastrotto, Yury A. Nikolaev, Elena O. Gracheva, Sviatoslav N. Bagriantsev
A major challenge in biology is to link cellular and molecular variations with behavioral phenotypes. Here, we studied somatosensory neurons from a panel of bird species from the family Anatidae, known for their tactile-based foraging behavior. We found that tactile specialists exhibit a proportional expansion of neuronal mechanoreceptors in trigeminal ganglia. The expansion of mechanoreceptors occurs via neurons with intermediately and slowly inactivating mechanocurrent. Such neurons contain the mechanically gated Piezo2 ion channel whose expression positively correlates with the expression of factors responsible for the development and function of mechanoreceptors. Conversely, Piezo2 expression negatively correlates with expression of molecules mediating the detection of temperature and pain, suggesting that the expansion of Piezo2-containing mechanoreceptors with prolonged mechanocurrent occurs at the expense of thermoreceptors and nociceptors. Our study suggests that the trade-off between neuronal subtypes is a general mechanism of tactile specialization at the level of somatosensory system.
https://www.sciencedirect.com/science/a ... 4719301378

The Mechanoreceptor Organs of the Lamellirostral Birds (Anseriformes, Aves)
K. V. Avilova, A. G. Fedorenko, N. V. Lebedeva
Two types of surface tactile epidermal formations are identified in the bill tip organ of 11 species of lamellirostral birds. Their density arrangement and ratio in the mandible and maxilla are greater in dabbling ducks (filter-feeder species) than in herbivorous and in actively pursuing species. The length and proportions of the connective tissue tubules enclosing the encapsulated mechanoreceptors in filter-feeder species differ significantly from the others. The vibroreceptor endings are significantly more numerous in filter-feeder species and the touch endings in nonfiltering ones. The latter are smaller in the filter-feeder species. Within the walls of the connective tissue tubules, tactile epitheliocytes are registered for the first time. The structure of keratinocytes separating epidermal papillae of the bill tip organ apparently ensures their mobility. The bill tip organ is probably involved in the communication process of waterfowl.
https://www.researchgate.net/profile/Na ... s-Aves.pdf

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Post by Anne7 » August 26th, 2019, 3:49 pm

Bird Senses

5. Taste

Nutrient sensing, taste and feed intake in avian species
Shahram Niknafs and Eugeni Roura
Abstract: The anatomical structure and function of beaks, bills and tongue together with the mechanics of deglutition in birds have contributed to the development of a taste system denuded of macrostructures visible to the human naked eye. Studies in chickens and other birds have revealed that the avian taste system consists of taste buds not clustered in papillae and located mainly (60 %) in the upper palate hidden in the crevasses of the salivary ducts. That explains the long delay in the understanding of the avian taste system. However, recent studies reported 767 taste buds in the oral cavity of the chicken. Chickens appear to have an acute sense of taste allowing for the discrimination of dietary amino acids, fatty acids, sugars, quinine, Ca and salt among others. However, chickens and other birds have small repertoires of bitter taste receptors (T2R) and are missing the T1R2 (related to sweet taste in mammals). Thus, T1R2-independent mechanisms of glucose sensing might be particularly relevant in chickens. The chicken umami receptor (T1R1/T1R3) responds to amino acids such as alanine and serine (known to stimulate the umami receptor in rodents and fish). Recently, the avian nutrient chemosensory system has been found in the gastrointestinal tract and hypothalamus related to the enteroendocrine system which mediates the gut-brain dialogue relevant to the control of feed intake. Overall, the understanding of the avian taste system provides novel and robust tools to improve avian nutrition.
https://www.cambridge.org/core/journals ... FF0E2A58A0

Comparative Taste Biology with Special Focus on Birds and Reptiles
Hannah M. Rowland, M. Rockwell Parker, Peihua Jiang, Danielle R. Reed, and Gary K. Beauchamp
Perhaps with the exception of young children, most modern humans are unfamiliar with experimenting with novel and potentially poisonous foods. Thus, our consciously appreciated sense of taste is valuable primarily only inasmuch as it adds pleasure (or displeasure) to dining. We no longer depend upon taste to be the nutrient sensor and early-warning system as it originally served. And if we pause to contemplate the gustatory experience of other animals, we may assume that it is much like our own or perhaps, for some species, like birds, that it is nonexistent. However, this assumption is incorrect. New discoveries from molecular biology and genetics describe the genes and proteins that contribute to taste as a sensory system, and together with mounting evidence from behavioural studies, we have a different story – every organism lives not only in its own dietary niche but, within that niche, also in its own unique world of taste perception and preference. This point was made by Morley Kare more than half a century ago (see Kare, 1970) and is implied by Darwin in the epigraph above.
A striking example of this species variation is the response of animals to sweet fruits. For humans, ripe fruit produces a sensation of pleasure and motivates consumption; it also invokes consumption in nonhuman primates, fruit-eating bats, and rodents, but cats and chickens are indifferent to sweet foods. We ask why – sugar is a source of energy and a signal of nutrients, so why would some animals not like sugar? Cats and chickens both have diets mostly devoid of sugar, which is associated with the evolutionary loss of a gene involved in sweet perception, a gene that humans and most other vertebrates that consume plants still possess. This type of example has inspired the burgeoning integrative eld called comparative taste biology, which draws on genetics, anatomy, physiology, behaviour, and psychology. As comparative taste researchers, we aim to understand the adaptations of animal taste system by examining their feeding behaviour, taste preferences, and the underlying molecular and physiological processes that mediate them.
https://www.researchgate.net/profile/M_ ... iology.pdf

Birds Generally Carry a Small Repertoire of Bitter Taste Receptor Genes
Kai Wang, Huabin Zhao
As they belong to the most species-rich class of tetrapod vertebrates, birds have long been believed to possess an inferior taste system. However, the bitter taste is fundamental in birds to recognize dietary toxins (which are typically bitter) in potential food sources. To characterize the evolution of avian bitter taste receptor genes (Tas2rs) and to test whether dietary toxins have shaped the repertoire size of avian Tas2rs, we examined 48 genomes representing all but 3 avian orders. The total number of Tas2r genes was found to range from 1 in the domestic pigeon to 12 in the bar-tailed trogon, with an average of 4, which suggested that a much smaller Tas2r gene repertoire exists in birds than in other vertebrates. Furthermore, we uncovered a positive correlation between the number of putatively functional Tas2rs and the abundance of potential toxins in avian diets. Because plant products contain more toxins than animal tissues and insects release poisonous defensive secretions, we hypothesized that herbivorous and insectivorous birds may demand more functional Tas2rs than carnivorous birds feeding on noninsect animals. Our analyses appear to support this hypothesis and highlight the critical role of taste perception in birds.
https://academic.oup.com/gbe/article-pd ... evv180.pdf

Comparative biology of taste: Insights into mechanism and function
Gary K Beauchamp & Peihua Jiang
Each animal lives in its own sensory world that is coordinated with its diet. In this brief review, we describe several examples of this coordination from studies of the sense of taste, particularly from species of the order Carnivora. This order includes species that are obligate carnivores (e.g., Felis species), omnivores, and strict plant-eaters. Many of the obligate carnivores have lost function for sweet taste, presumably through relaxation of selection for eating sugars from plants. In contrast, the giant panda, which feeds almost exclusively on bamboo, retains sweet taste function but may have lost amino acid (umami) taste perception. Finally, mammals that have “returned” to the sea, such as sea lions, have experienced even more extensive taste loss, presumably as a consequence of adaptations to a diet of fish and other sea creatures swallowed whole. Future comparative studies will surely reveal important relationships between diet and molecular, cellular, and behavioural taste adaptations that will shed light on how evolution moulds sensory structure and function.
Each animal species lives in a separate sensory world that is coordinated with its behavioural ecology. A dramatic example of this occurs for the sense of taste where sensory perception and diet choice are intimately intertwined. ...
... A striking study with birds provides additional support for the hypothesis that sweet taste exists to detect simple sugars. All birds apparently lack a homolog for the Tas1r2 gene; this loss likely occurred as the non-avian reptile and bird lines split. Thus, it would seem that birds should not be able to taste sweet sugars. But if this were the case, how can one explain the behaviour of avian species that consume sweet sugars such as hummingbirds? Baldwin et al. provide one answer: The receptor dimer T1R1 + T1R3, the amino acid or umami receptor in mammals, has been repurposed in these bird species to detect simple sugars thereby opening a novel source of energy not available to many other birds. In sum, these studies provide strong support for the hypothesis that sweet taste perception exists to provide an ability to identify energy-rich sugars. ...
https://flavourjournal.biomedcentral.co ... 4-7248-4-9

Contrasting morphological evidence for the presence of taste buds in Dromaius novaehollandiae and Struthio camelus (Palaeognathae, Aves)
Martina Rachel Crole, John Thomson Soley
This study, facilitated by the use of immunohistochemistry, indicated the presence of taste buds in Dromaius novaehollandiae but not in Struthio camelus. Seen at the light microscope level, the taste buds consisted of follicular cells and receptor cells. The follicular cells were located at the periphery of the taste bud, essentially encapsulating the receptor cells. Two morphologically distinct receptor cells were identified. Immunohistochemical labelling for neurofilament identified gustatory nerves within the taste bud. The distribution of taste buds in D. novaehollandiae matched strategic locations in the oropharynx along which food could be sampled, according to the feeding method described for these birds. Future feeding studies would be necessary in D. novaehollandiae to determine the importance of taste discrimination in their diet. This study represents the first confirmed report of a sense of taste in any ratite species.
https://repository.up.ac.za/bitstream/h ... sequence=1

Evolution of sweet taste perception in hummingbirds by transformation of the ancestral umami receptor
Maude W. Baldwin, Yasuka Toda, Tomoya Nakagita, Mary J. O'Connell, Kirk C. Klasing, Takumi Misaka, Scott V. Edwards, Stephen D. Liberles
Sensory systems define an animal's capacity for perception and can evolve to promote survival in new environmental niches. We have uncovered a noncanonical mechanism for sweet taste perception that evolved in hummingbirds since their divergence from insectivorous swifts, their closest relatives. We observed the widespread absence in birds of an essential subunit (T1R2) of the only known vertebrate sweet receptor, raising questions about how specialized nectar feeders such as hummingbirds sense sugars. Receptor expression studies revealed that the ancestral umami receptor (the T1R1-T1R3 heterodimer) was repurposed in hummingbirds to function as a carbohydrate receptor. Furthermore, the molecular recognition properties of T1R1-T1R3 guided taste behaviour in captive and wild hummingbirds. We propose that changing taste receptor function enabled hummingbirds to perceive and use nectar, facilitating the massive radiation of hummingbird species.

Sensing nectar's sweetness
Peihua Jiang, Gary K. Beauchamp
In a brief comment on the sense of taste, Charles Darwin noted that “Real taste [in] the mouth, in my theory must be acquired by certain foods being habitual—[and] hence become hereditary” (1). This view, that taste perception and diet form a coordinated evolutionarily guided system, has received renewed support from recent behavioural, physiological, and molecular studies of comparative taste. On page 929 of this issue, Baldwin et al. (2) describe a striking example of this coordination in sweet nectar-eating hummingbirds—the repurposing of an amino acid taste receptor to respond to sugars and other sweeteners, permitting these birds to occupy a whole new avian niche.

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Post by Anne7 » August 27th, 2019, 3:54 pm

VII International Conference on Black Stork Ciconia nigra

Doñana National Park, Spain. 28th-30th November 2018

http://forestiersdumonde.org/wp-content ... t-Book.pdf

PART 1. Black Stork Population and Trends

Males, Females and Black Stork Nests: Who Owns What and Do They Hold Territories?
Maris STRAZDS, Laboratory of Ornithology, Institute of Biology, University of Latvia, Latvia
Extensive ringing programme of Black Stork juveniles in Latvia started in 1990. Up until 2017, 1,603 juvenile storks had been ringed. In 2011, first remote sensing cameras were installed, and one of the nests has been permanently observed with a webcam since 2015. As of 2016, data from 20 cameras can be explored simultaneously. Obtained material comprises more than 1.2M pictures collected near 92 nests. From this material, more than 772K pictures from 41 nests, along with the videos filmed at two webcam-equipped nests, have been used for analyses of territorial behaviour and mate choice during the breeding season. In this talk, I discuss the validity of the widely explored concept of the "territorial” or “non-breeding pair" – a parameter that strongly affects all indices of productivity for any given territory. The data obtained exclusively from observations of ringed individuals with known sex and other individually identifiable birds suggest that this term is not relevant for Black Stork, consequently, all breeding success data should be reassessed. Similarly, the assumption that males own the nest appears not to be correct at least in some cases. The question whether it is true only for Storks in the surveyed range or characterises species as a whole should be the subject of a wider study over much larger territory in the future.

The National Black Stork Census in the Czech Republic in 2014
Nature Conservation Agency of the Czech Republic, Kaplanova 1931/1, CZ 148 00 Prague, Czech Republic
To the results of the 3rd National Black Stork Ciconia nigra Census carried out in 2014, data from 2015 and 2016 were added. Using the data gathered the breeding population was estimated at 505 breeding pairs in the Czech Republic, thus corresponding to modelled estimation made in 2009, i.e. 524 pairs. The results were compared with previous censuses implemented in 1994 and 2004 (an increasing trend): it seems that the carrying capacity in the Black Stork breeding population has been reached across the country.
The nesting tree selection and its changes in 1930 – 2014 was analysed based on 740 data in total, gathered in 1965, 1990, 1994, 2004 and 2014. During the whole period studied, black storks used the European beech most frequently (30 %). Moreover, the European larch has gradually but significantly been preferred, reaching 26 % in 2014, while in 1965 it was 2.3 % only. A detail analysis of habitats at nesting sites (data for 1994, 2004 and 2014, areas of 10, 50 and 100 square kilometres around the nest) shows that in close proximity to the nest forests (58 %) prevail followed by arable land (22 %) and meadows (17 %) while human settlements cover 2 % there. Generally larger area and longer period studied result in decrease in forest proportion and in increase in human settlement/built-up coverage. Among forest types within the area of 100 km2 around the nest, coniferous managed forests are the most common (64 %): mixed (24 %) and deciduous broad-leaved forest growths (24 %) have been selected by black storks less frequently. It can be concluded that the habitat selection reflects land-use and habitat types proportion/distribution as well as the state of the landscape in the Czech Republic.

The Status of Black Stork Population in Belarus Polesie
The State Scientific and Production Amalgamation "Scientific and practical centre of the National Academy of Sciences of Belarus for biological resources, Minsk, Belarus
The study was carried out in Belarus Polesie (Stolin district, Brest region). The monitoring plot (95 km2) is located in the valley of the Pripyat River.
Monitoring of the Black Stork Ciconia nigra population number in 2011-2018 showed a small fluctuation in the number of territorial pairs (the density was 24-30 pairs per 100 km2 of forest). Breeding success was changing from 0.5 to 1.4 chicks per territorial pair. The number of chicks per successful pair varied from 2.2 to 3.4. During some years up to 67% of pairs do not start nesting (they visit nests, but do not start breeding).
A significant decline in breeding success was noted in 2015 and is still ongoing (during 2015-2018 breeding success was 0.5-0.8 chicks per pair). We associate this with drought and with a significant decrease in the number of frogs in the forest (from 600-700 individuals per 1 km of route accounting in 2013 to 1-20 individuals per 1 km of rout accounting in 2015-2018). In previous years, frogs were the main food of the Black Stork chicks at the monitoring plot. During the years when the frogs disappeared, the main food of the chicks was small fish.
In 2015-2018 the causes of death of chicks were identified with the help of camera-traps (44 nesting attempt were traced). In our studies, the following animal species were the cause of unsuccessful nesting:
1. Goshawk Accipiter gentilis – one nestling was killed.
2. White-tailed Eagle Haliaeetus albicilla. In 2015, 2016, 2017 and 2018 we recorded one case of Black Stork nest destruction per one breeding season. Before 2015, we did not find nests that were ravaged by White-tailed Eagle.
3. Black Stork Ciconia nigra. Two cases of destruction of clutches were recorded because of the attack of other individuals of Black Storks (not from its pair).
Thus, the local population of the Black Stork in the Belarusian Polesie is in a relatively stable state. However, changes in weather conditions (drought) and the subsequent deterioration of the food supply may lead to a drop in the number of the species in the future. Among local species of predators, White-tailed Eagle causes the most significant damage to the local population.

Monitoring of the French Black Stork Population
Nicolas GENDRE (LPO France Birdlife), Jean-Jacques BOUTTEAUX (ONF) and Frederic CHAPALAIN (LPO – Birdlife – CRBPO)
Black stork Ciconia nigra, is a heritage species reappeared in France in 1977. It has been the subject of several studies and monitoring programmes at national and regional level. The LPO France – ONF, in coordination with the banding programme, allows an annual national synthesis and a coordination of the different actors. The National Forestry Office (ONF) carries out specific actions to take into account the species in forest management. The majority (66%) of known Black Stork nests are located in public forests (state forests and communal forests) managed by the ONF. In 2017, the LPO France - ONF coordination became aware of 55 nests occupied in France. Those frequented sites without follow-up at the beginning of the season are not counted. As 100% of the nests have not been discovered, it is reasonable to estimate the French breeding population are about 70 pairs (60-80 pairs) in 2017. Breeding pairs of Black Stork are mainly located in the North-eastern part of France.

Trend of Black Stork Ciconia nigra Population in Spain
1 Department of Zoology and Physical Antropology, Faculty of Biology Sciences, Complutense University, 28040 Madrid, Spain
2 IUCN SSC Stork, Ibis and Spoonbill Specialist Group. Rue Mauverney 28, 1196 Gland, Switzerland

The Black Stork Ciconia nigra breeds throughout the Palaearctic and includes populations in the southern tip of Africa. The European breeding population is composed of one large population that ranges from Russia to France and from Baltic countries to Greece and Italy, with one small population in the Iberian Peninsula, geographically isolated at the western corner of the Palaearctic. This study updates the current size and geographical distribution of the breeding population of Black Stork in Spain (2017 breeding season) based on number of active breeding pairs present on nest at the beginning of the breeding season that has been reported directly by regions and experts, and offer additional interpretation of the results on the Breeding Population Census 2017 published by SEO/BirdLife. The current population size and distribution is compared with the population data obtained in 2002 (one generation for this species), using the same criteria. In 2017, the number of active breeding pairs was less than 2002, but there is not a statistically significant difference between periods. The geographical distribution of the species during the breeding period has not changed either. This shows a stabilization of the breeding population of the Black Stork in Spain after two decades of increase. This information should be taken in account to review the conservation status of the small Iberian population.

Distribution and Population Change of Black Storks in China
Junwei LI and Roller MAMING
Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, No. 818 Beijing Road, Urumqi, 830011, Xinjiang, P. R. of China.
Black stork Ciconia nigra is an endangered species in the world, and the first-grade protected wild bird in China. At present, we know there are only 24,000 ~ 44,000 in the world, and there are about 1,900 ~3,600 in China. It is a breeding and seasonal migratory bird that is distributed almost all over the country. The main breeding grounds are northeast of the Yellow River Basin (Heilongjiang, Jilin, Liaoning), North China (Beijing, Hebei, Shanxi, Shandong) and Northwest China (Xinjiang, Gansu, Qinghai). During the migration, it passes through Lop Nur of Xinjiang, Liao River Delta of Liaoning, Beidaihe of Hebei, Yellow River Beach of Huayuankou in Henan. The wintering areas are the Yangtze River Basin and South China and Southwest China (Yunnan, Hunan, Hubei, Henan, Hebei, Jiangxi, Beijing, Anhui, etc.). Although it is widely distributed, its number is scarce. Therefore, it has been listed as an endangered species by the Red Book of China's Endangered Animals (1998).
In the past 10 years, local researchers have continuously monitored the dynamics of populations of Black Stork throughout the country. The results show that: In the winters of 2004~2005, 2007~2008, and 2008~2009, the average number of overwintering Black Stork populations at the Napahai wetland in Yunnan province was 40, 129 and 182, respectively. From 2010 to 2012, the number in the national nature reserve of Heihe River Wetland in Gansu was 310, 380 and 430, respectively. It can be seen that the number is increasing year by year. From 2003 to 2009, the number of Black Storks in the Juma River of Shidu Nature Reserve in Beijing was 15~28 in winter. From 2004 to 2007, 30, 40, 70 and 130 black storks were recorded annually in Gahai lake region of Gansu. From 2005 to 2010, the quantity of Black Storks in the Yehe River of Hebei was monitored, it was found that the population in 2005 was the highest, with an average number of encounters of 8 per month and a maximum population of 14. In 2009, the population was the lowest, with an average number of encounters of 2 per month and a maximum of 7. This indicates that the number of Black Storks in the region showed a decreasing trend.
Xinjiang is the largest province in China, accounting for one sixth of the territory, with a large number of Black Storks. The Tarim Basin is the main breeding ground and distribution area of the largest population of Black Storks in China. During the winter, Black Storks in Xinjiang migrated to South Asia. From March to April, they flew back to the Tarim River, Urumqi, Irtysh River and Aibi Lake for breeding. They often nested in the shallow caves of mountain cliffs and riverside cliffs or on the tall poplar trees in the oasis wetlands, and had the habit of using the old nest. The number of breeding population in Xinjiang was estimated to be 900~1300, and the number of migratory/passing population is 600~800, it is 1,500~2,100 totally.
We know around the world the number of Black Storks has declined significantly in recent years, it is necessary to understand the reason. Based on the long-term monitoring of Black Storks in different regions, the reasons for the decline of the number of Black Storks are mainly as follows: Habitat degradation, illegal hunting (bird nets, shotguns, poisons, etc.), polluted, human disturbance (tourism activity), electric shock and collision. In view of this, we strongly call on local people and government to pay full attention to the population dynamics of Black Storks, and recommend that relevant departments to actively publicize laws and regulations, and take effective measures to curb illegal hunting activities, and effectively increase people's awareness of protecting wetlands and cherishing wildlife resources. It is hoped to create a good living, breeding and habitat environment for the Black Storks by establishing nature reserves, protecting its habitat and reducing environmental pollution.

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Post by Anne7 » August 27th, 2019, 3:55 pm

VII International Conference on Black Stork Ciconia nigra

Doñana National Park, Spain. 28th-30th November 2018

http://forestiersdumonde.org/wp-content ... t-Book.pdf

PART 2. Threats and Conservation of Black Stork

Black Storks in Captivity: What Role Can They Play in Conservation?
C. KING (Weltvogelpark Walsrode, Germany), A. BRAČKO (Zagreb Zoo, Croatia) and R. TOPOLA (Warsaw Zoo, Poland)
While Black Storks Ciconia nigra are found in zoos as far away as Japan and the United States of America, according to Species 360, an international record keeping system, almost all of zoos holding Black Storks (79 of 84, 94.0%) are within the European Association of Zoos and Aquaria (EAZA) region. Likewise, 186 of 208 (89.4%) specimens are in the EAZA region. There has been an EAZA European Studbook program (ESB) for this species since 1996, and Ryszard Topola (Warsaw Zoo, Poland) has been the studbook keeper since its inception. This program is managed under the umbrella of the EAZA Ciconiiformes and Phoenicopteriformes Taxon Advisory Group (TAG), which is responsible for providing direction in captive management of species included in the TAG in areas such as selection of species to keep, husbandry, welfare, research and conservation. The TAG also acts works with colleagues in other regions and acts as a bridge between in situ and ex situ efforts.
The ESB is useful to not only to keep track of individuals and population genetic diversity, but to gather data on demographically relevant characteristics. For example, potential longevity is more likely to be achieved in the captive situation, and it is possible to look at age related fecundity and whether reproductive senescence occurs. There are some issues that need to be resolved to improve Black Stork captive management, for example males are more likely to kill females than in most commonly held storks.
The global zoo community is now embracing the One plan Approach to conservation, which can be defined as is the development of management strategies and conservation actions by all responsible parties for all populations of a species, whether inside or outside their natural range. Since Black Storks are not globally threatened, a captive breeding program for Black Storks as a backup population, or for reintroduction, is unwarranted. However Black Storks are a very suitable species for educating the general public about the importance of conserving forest and wetland habitats, and can also be helpful in explaining complex concepts such as rewilding that are pertinent to Black Stork conservation. Wild Black Storks coming into the EAZA population now are often from rehabilitation centres, and can help create awareness about the hazards that birds face such as powerlines, particularly during migration. If a threat arises to the natural habitat, such as putting a major road through the Danube Delta, it could be possible for zoos, especially local ones, to help educate the public about the threat and encourage them to take action to protest it.
Captive individuals can also aid in researching physiological, behavioural, morphological and other such parameters that are difficult to study in an often elusive forest dwelling species such as the Black Stork. Trials to test tagging or other equipment can easily be undertaken with captive individuals. Black Storks can possibly serve as a model for management of more threatened closely related species, such as the IUCN Red listed Endangered Storm’s Stork Ciconia stormii, which is both ecologically and taxonomically closely related.
These are just some examples of how captive Black Storks might be helpful in conservation; we would like to hear from people in the field how the EAZA community can help further their efforts.

Problems of Black Stork Conservation in Ukraine
Andriy BOKOTEY, Natalie DZIUBENKO and Iuriy STRUS
State Museum of Natural History, NAS of Ukraine, Lviv, Ukraine

Black Stork is listed in the National Red Data Book in Ukraine, but despite high conservation status, there were no practical measures for species conservation foreseen in the national legislation until recent times. Only at the end of 2016, the concept of a protection zone around raptors and Black Stork nests was introduced into the national legislation of Ukraine. However, if in the case of raptors sizes of protection zones are similar to international standards, in the case of Black Stork the radius of a zone was chosen equal to 1,000 m during the whole year. It is obvious that such changes provoked a strong reaction in the forestry industry. Around a single nest, up to 314 Hectares of forest are forbidden of forestry use. Usually, it is premature or mature forest with the highest value for the industry. This caused concealing of information by forestry workers about presence and location of Black Stork nests on forest territories. We even registered cases when forestry workers have destroyed nests to continue industrial activities.
We surveyed the territory around 141 Black Stork nests in Ukrainian Polissia area. Logging of forests was detected around 37.3% of nests within 100 m radius. In more than 14% of plots (within 100 m) forest loss is higher than 20% of the total area. All this allow us to suggest that forest logging is still the main threat for Black Storks in Ukraine.
On the basis of obtained results and our 12-year research within the “Ciconia-Ukraina” project, we have developed the National Action Plan to protect the Black Stork in Ukraine during the following 5 years. In the plan, seasonality and optimal sizes of protection zones are foreseen. This plan is already approved by the Ministry of Ecology and Natural Resources of Ukraine and will be implemented in 2019.
This step will improve the protection of Black Stork breeding sites because in Ukraine, during the last decade, area of forests is constantly decreasing and number of trees older than 80 years, potentially suitable for nesting of Black Storks, is less than 10%.

Conservation Results of Black Stork Tracking and Webcam Use
Eagle Club, Hauka, Estonia

In Estonia we started tracking of Black Stork together with several other European countries within Flyover Nature 2000 project and with kind practical tutorials of Czech colleagues in 2005. Since then, we tracked 26 Black Stork individuals, including 12 adult males, 5 adult females and 9 juveniles. Tracking time span varied since few months up to 12 years.
We used web cameras for real-time transmission (with free public access) since 2007, every year one nest has been monitored via webcam. Altogether three different nests followed having different breeding success in different years. Between 2008 and 2018 juveniles of webcams nests have been (or are currently) tracked. Depending on breeding success in real-time monitored nests, the click number per year were from 0,15 up to 6 Million. That means around eight-ten times less users in general.
What can we list among conservation results? Home range use, nest site change, foraging sites use (especially during feeding of chicks), visiting of neighbouring nests, breeding success, infanticide, predation, arrival time, departure time, using of resting sites, migration routes, using of migration stopover sites, wintering sites, survival rate – these seem to be classical conservation aspects (not complete) to follow and investigate.
But, what about education and rising of awareness? Probably everybody agrees that above-mentioned conservation aspects once studied, wouldn’t be to share between specialists only. But need to be highlighted for decision makers in society! Means not to be lost in enormous amount of information we all need to stand with, everyday…
Therefore, web cameras with free access, quality image and audio we launched to build up some part of society being in touch with Black Stork nest life and breeding needs. After nest life ends and nothing to look for dedicated people, we can invite them to look for migration of their beloved birds – using the public migration map for example-. That is to invite people to follow migration, to understand threats during migration and wintering. Maybe it is a part of open data initiative to support citizen science. These initiatives invite people not only watch, but also to ask the questions… and find the answers by themselves. To find answers, more scientific papers are invited to be published by scientists. Fortunately, we have quite a good set of papers, but much more we have data about Black Storks in different countries.
In general, conservation legislation for Black Stork in Estonia is efficient to protect nest sites, there are more nest sites protected as we have individuals. But almost nothing about protection of feeding sites (except nature reserves). Other sides, feeding sites are situated far of nest site (up to 45 km). What to do to enhance the foraging areas? Restoration of natural streams (in protected plots, everywhere?) may be the case in Eastern European range. Quicker and easier way is to open partly good streams with food there. We used during last three years volunteer camps for that purpose in 16 cases. Additional value was education of those people about Black Stork. For next two years we have accepted project for to make an inventory of potential Black Stork feeding streams in Estonia (first in protected sites, then around currently occupied nest sites and latter in economical forest). That is to suggest restoration measures for next projects to restore degraded streams. Also, restoration of one sample site is foreseen there in project. For to monitor results of project, few tracking devices are planned to install.

The Hazards of Overhead Electric Lines on Black Storks
Béla KALOCSA, and Enikő Anna TAMÁS
MME BirdLife Hungary

Almost every year the death or serious injury of Black Storks caused by overhead electric lines is recorded in the Hungarian ringing database. Among the Black Storks with satellite transmitters from Hungary, the prevalence of electrocution and collision with overhead electric wires is very high. This is a considerable threat not only near the breeding grounds but along migration routes as well. MME BirdLife Hungary has been working for years in order to decrease the risks posed by overhead electric lines, as the threat affects other species as well (including the White Stork Ciconia ciconia and different raptors). Communication and co-operation with electricity providers and the importance of international co-operation is also outlined.

Study of the Flight Behaviour of Black Storks in Relation to Weather Conditions and Land Use with Special Consideration of Existing Wind Turbines in the SPA Vogelsberg (Hessen - Germany)
Patric LORGÉ
BirdLife Luxembourg - Centrale Ornithologique (COL)

Main target of this research project was the improvement of knowledge of the flight behaviour of the Black Stork depending on weather conditions and land use. In addition, flight behaviour in close proximity to wind turbines (WEA) was analysed.
The Vogelsberg nature reserve was chosen as project area because of several local breeding Black Stork pairs and two wind farms located in the same area.
The flight behaviour was determined by visual observation of the perceptible flights in relation to Altitude (vertical) and species-specific behaviour patterns were categorized. The influence of the weather and land use has been checked by statistical analysis.
For the analysis of the flight behaviour in the close range to WEA, a radius of 250 m around the WEA was defined as danger zone. When approaching this danger zone, a detailed description of the flight movement (vertical and horizontal) was made under consideration of weather data and wing tip speed of the WEA. Potential and used feeding habitats were also taken into account. The recording of flight movements took place from 01.04. to 11.08.2016, resp. on 40 recording days with simultaneous synchronous counts (640 hours).
Flight behaviour in the WEA-environment
Within the present study, Black Storks approached WEA in 10 out of 121 flights (8.3 %) to such an extent that they can be placed within the critical danger zone (250 m horizontal consideration). Flights through wind farms have not been observed in this study, but were reported in others. The weather conditions for flights in the danger zone were always favourable (no precipitation, no high wind speeds, optimal visibility). The WEA were in operation during the flights. Several other studies were analysed and results compared to the present study.
Influence of the weather and land use on the flight altitude of the Black Stork
In the present study, no statistically supported model could be found, which determines the probability of the occurrence of flights in the rotor height in correlation with weather parameters. There is no significant influence of the weather on the flight altitude in the danger area. However, it is likely that thermals play a role in flight altitude, especially during very long flights.
Land use has no influence on the spatial distribution of flight activity.
It must be said that these conclusions were drawn from the observation of a small number of Black Storks and are therefore not worth generalizing.
Therefore, it would be important to carry out further investigations (telemetry of breeders close to wind turbines) in particular with new GPS transmitters with simultaneous acquisition of elevation data in order to obtain more detailed information on flight altitude and space use as well as on the use of food habitats and main action areas. In addition, telemetry studies should be conducted for at least 3 to 5 years.
As a conclusion of this study and the evaluation of existing studies, several successful breeding cases of Black Storks within a radius of 3,000 m to existing wind turbines were recorded.
Overall and despite the fact that some breeding sites are only a short distance from the nearest wind turbines (550 m to 1,300 m), only a very small proportion of the total number of flights can be regarded as conflict-prone. For almost all these flights, a peripheral flight around the WEA was observed.
During the study, no collisions were detected and no adult breeder birds disappeared, so that collisions in the study period are ruled out. This study shows that the studied Black Storks can come close to the WEA in operation and actively fly around, over or/and cross wind farms in a "manageable situations" or with a sufficiently wide corridor.
Summary provided by Patric Lorgé. The original study in German and maps can be obtained here:
https://landesplanung.hessen.de/informa ... warzstorch

Black Stork and Wind Farm: Which Level of Risk? Case of Mortality, Sample of Measures Proposed to Take into Account Wind Farm Risks, Open Discussion Session to Compare Different European Experiences
Frederic CHAPALAIN (LPO France Birdlife – CRBPO) and Nicolas GENDRE (LPO France Birdlife)
In the last ten years, we have witnessed in France a real explosion in the number of wind farm projects. In 2017, France occupies the 4th position in wind farms in Europe and there is a plan to double its fleet in the next 10 years. These projects with strong political and economic interests are accompanied by previous impact studies and monitoring studies after the implant. The Black Stork, a rare species with a great heritage and vast territory, is taken into account in these studies when this presence is demonstrated. These Environmental Impact studies, which quality is very variable and generally very insufficient for this species, are neither standardized nor independent because they are carried out by the promoters or their subcontractor/s. This makes almost impossible to get information back. National LPO-ONF in coordination with various actors in the field is regularly interviewed by wind farm agents. Measuring the impact of these facilities is difficult. To date, a corpse of a Black Stork has been found.

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Post by Anne7 » August 27th, 2019, 3:56 pm

VII International Conference on Black Stork Ciconia nigra

Doñana National Park, Spain. 28th-30th November 2018

http://forestiersdumonde.org/wp-content ... t-Book.pdf

PART 3. Ecology and Behaviour of Black Stork

Diet of the Black Stork in the Czech Republic
Nature Conservation Agency of the Czech Republic, Kaplanova 1931/1, CZ 148 00 Prague, Czech Republic

2nd Records on Black Stork young food found on nests in Central and West Bohemia in 1994-2012 confirm the dominancy of fish. The food analysed was mostly that thrown out by nestlings during their ringing. Fish significantly dominated in the Black Stork nestling diet (89.4 % by numbers), followed by lampreys (4.9 %) and amphibians (2.8 %). Mammals (1.21 %), reptiles (0.4 %) and invertebrates (1.2 %) were less important. The freshwater Brown Trout Salmo trutta was the most abundant prey (35.7 %), while the Common Roach Rutilus rutilus, Common Carp Cyprinus carpio, European Perch Perca fluviatilis and the Tench Tinca tinca were preyed less frequently. The fish/Brown Trout captured mean size was 17.29 cm, while the mean weight was found to be 68.1 g.

The First Documented Case of Northern Goshawk Accipiter gentilis Predation on Black Stork Ciconia nigra Nestlings
Bartosz JANIC1, Maciej KAMIŃSKI1, Dariusz PIENIAK2, Michał STRAWIAK3 and Piotr ZIELIŃSKI1
1 Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16; 90-237 Łódź, Poland.
2 Institute of Forest Sciences, University of Lodz Branch in Tomaszow Mazowiecki, Konstytucji 3 Maja, 97-200 Tomaszów Mazowiecki, Poland.
3 Leśny Zakład Doświadczalny SGGW w Rogowie, ul. Akademicka 20, 95-063 Rogów, Poland.

In 2016 and 2017 five instances of the Northern Goshawk Accipiter gentilis depredating Black Stork Ciconia nigra nestlings were observed using web camera installed at a Black Stork nest in central Poland. In 2016 the Goshawk depredated whole brood of three Black Stork nestlings. The nestlings’ ages at the time of the attack were 23, 21 and 23 days. In 2017, at the same nest, the Goshawk partially depredated the brood, removing two (age 21 and 24 days) out of the four nestlings. In 2018, in other nest with web camera, the Goshawk depredated whole brood of five nestlings (age 26, 29, 35, 37 and 38 days). It is suggested that the impact of the Goshawk predation on Black Stork broods is much stronger than previously thought. This study was a part of a Black Stork joint project of the Regional Directorate of State Forests in Lodz, the Eagle Conservation Committee and the University of Lodz (2016-2017) and the Regional Directorate of State Forests in Lodz and the University of Lodz in 2018.

New Data on Black Stork Nest Predators in Latvia
Māris STRAZDS1 and Linda OSE 1,2
1 Laboratory of Ornithology, Institute of Biology, University of Latvia
2 Faculty of Geography and Earth sciences, University of Latvia

We used trail cameras to collect more accurate data on Black Stork phenology, to collect ring recoveries of adult birds and to improve knowledge on the behaviour of Black Storks in Latvia since 2011. The total amount of data to be used for analyses comprises 9,351 camera days, with 5,218 days of stork presence, 1,141,248 pictures in total. These data among other things also document numerous visits of predators and show some depredation cases in detail. The new data have changed our understanding of significance of some of the known predator species, namely Goshawk Accipiter gentilis depredation is far more significant than was suspected earlier. Other important new finding is that many depredation cases are partial. This leaves some nests "depredated" but successful at the same time. Our data show that depredation during egg period is very strongly underrated and that partial depredation is most frequently not registered at all. We discuss the differences in patterns of attacks of various predator species and difficulties in discovering true causes of egg and/or chick loss during breeding season.

Possible Reasons of Unsuccessful Breeding and Cases of Parental Infanticide of Black Storks
Based on Nest Camera Observations

Béla KALOCSA, and Enikő Anna TAMÁS MME BirdLife Hungary
We have been observing Black Stork nests with cameras since 2005, in the first eight years at one nest and since 2013 at two nests, simultaneously, both in the Gemenc region of the Danube-Drava National Park, Hungary. During the 1,4 years, we observed on several occasions that the breeding has failed for different reasons. In our presentation, we try to give the reasons for nesting failure (e.g. weather, lack of food, predation). We have also observed several cases of parental infanticide and we are providing details on these cases in our presentation.

Habitat Preferences of Black Stork Nesting
SPC of NAS of Belarus for Biological Resources Minsk, Belarus

Studies of Black Stork Ciconia nigra habitat preferences are important to actualize the legislation on protection of Black Stork. Additionally, it is useful to select sites for building artificial platforms for Black Stork. In 2016-2017 we conducted a description of a number of characteristics of forest and other factors.
We studied habitat preferences between real Black Stork nesting places and random places (theoretically good for nesting) in forest environments, used as a control group. The study was conducted in Belorussian Polesie (Brest region) on 3 plots: Middle Pripyat (Stolin district, anthropogenic pressure is low, old forest, plot area is 95 km2, monitoring plot with all nests known), L'va (Stolin district, human activity exists, less old forest, plot area is 240 km2, monitoring plot with all nests known), Belovezhskaya Pushcha (Kamenec district, anthropogenic pressure is just absent, some of nests are known). Broadleaf and small-leafed swampy forests are dominating in Middle Pripyat and Belovezhskaya Pushcha and on L'va plot pine forests are dominating.
All 3 plots are different in tree density and age. Meanwhile, Black Stork habitat does not differ between plots significantly. Thus we can identify optimal habitat conditions for Black Stork nesting, which are same in all plots. Optimal density was 29.89 ind/500 m2 (±11.04) (N=148), tree diameter varies from 21.85 mm (±13.68) in L'va plot (N=633) to 24.68 mm (±15.14) in Belovezhskaya Pushcha (N=747). Projective cover ratio of bushes was 20.06 % (±20%), 38.96% in control (±34%). The role of bushes is mixed. They hide nests from predators, but in some cases, if Black Stork nest is very low, it can prevent Black Storks to visit their nest.

Moult Pattern as a Tool for Individual Identification of Black Storks
Laboratory of Ornithology, Institute of Biology, University of Latvia

Ability to distinguish a study subject individually is a very important pre-condition for any study that considers birds as individuals rather than species as such. The key method for individual marking of birds is marking them with rings, however, due to the secretive life-style and large dispersal distances of the Black Stork it is very difficult to reach a condition when high percentage of individuals in a studied population would have rings. To tackle this problem, I have used moult-produced pattern an as additional / alternative method. Moult is a process characteristic for all birds that is happening throughout their whole life, whereby worn feathers are replaced with new ones. Due to differences in the surface structure, worn and fresh feathers reflect light differently. In sunlight this effect is visible only if the light falls on plumage at a certain angle. Fortunately, pictures taken from a close range with an infrared light source in the dark produce different result: worn feathers appear very pale, while fresh feathers look almost black. Black Stork has 12 primaries and 22 secondaries and an equal amount of large coverts on each wing (68 x 2). If only these feathers are considered, the number of possible combinations is 8.7112285931e+40. If the 3rd stage is added (some feathers might be/are missing) then the total number of combinations reaches 7.7355401014e+64. Moult seems to be happening continuously, thus creating an unmistakable combination of pale and dark feathers – a real "bar code" individual for each bird. Although in theory two birds could have the same pattern of all feathers that is highly unlikely to happen in reality. If other feathers (medium and small coverts of wings, remiges and large feathers on the back) and other features suitable for identification (shape of the beak, face pattern, peculiarities and defects of plumage etc.) are considered, each bird has an unmistakeable fingerprint throughout the given season. The question whether changes in the moult pattern can be used to identify birds also between subsequent seasons is the subject of a further study, as more ringed birds are necessary with series of pictures from more than two seasons in a row.

Growth of Young Black Stork in the Czech Republic
1 Nature Conservation Agency of the Czech Republic, Kaplanova 1931/1, CZ 148 00 Prague, Czech Republic
2 Moskevska 1446/61, CZ 101 00 Prague

In 1994-2012, biometric data of 576 young on nests (nestlings/pulli) were gathered during Black Stork´s ringing activity in the Czech Republic, particularly in an area located west and southwest of Prague. In total, 1,325 data on three measurements, namely wing, beak and tarsometatarsus lengths were collected. From the data raised during Black Stork young rearing at the Prague Zoo the growth curve was constructed and regression lines were calculated describing the linear relationship between wing, beak and tarsometatarsus lengths and nestling age throughout the brooding period. Wing and beak growth has not been finished at the time were young is ringed at the nest and has further been continuing, while tarsometatarsus growth is finished at that period, reaching the size known in adults.
Daily growth rates in the period of linear growth are 9.1 mm for wing, 1.9 mm for beak and 3.6 mm for tarsometatarsus. From the data gathered, the date reaching the wing length having been determined in advance at 400 mm, i.e. at the age of 50 days was computed for each young. Thus, the baseline age value distribution (i.e., the particular days = date) was analysed in the respective years. The timing of breeding in the respective years was tested against shifting in the starting nesting in 1994-2012: it was confirmed that the nesting has started 4 days earlier in the course of the above period, possibly caused by step-by-step climate change.
Ring recovery data obtained for the young studied (in total, 83 individuals) in relation to their size (i.e., to their age) at the nest. It was found that the oldest and biggest young, i.e. “first-born”) predominate among the recovered birds, assuming that they better survive (the latter are being better genetically fitted for survival, displaying better fitness).
For determining the age in young on the nest based on lessons learnt, it is recommended when determining the nestling age to measure the total wing size, the beak size respectively, the latter being the supplementary information for checking the calculation. The one-day margin for error corresponds with the accuracy/exactness of measurements and with the daily growth rate in both the parameters studied.

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Post by Anne7 » August 27th, 2019, 3:57 pm

VII International Conference on Black Stork Ciconia nigra

Doñana National Park, Spain. 28th-30th November 2018

http://forestiersdumonde.org/wp-content ... t-Book.pdf

PART 4. Movements, Tracking, Ringing & Migration of Black Stork

What Makes a Successful Migrant?
Lessons from a Five Year Tracking Project of a Long Distance Migratory Species

Maris STRAZDS1, Wolfgang FIEDLER2 and Hans-Günther BAUER2
1 Laboratory of Ornithology, Institute of Biology, University of Latvia, Latvia
2 Max Planck Institute of Ornithology, Germany

In 2013-2017 we have tracked 27 juvenile Black Storks Ciconia nigra with GSM transmitters from Latvia (NE Europe). Contrary to many migratory species, Black Stork is a solitary traveller. Juvenile birds during their first migration from northern Europe to trans-Saharan Africa must rely upon the resources they received at the nesting site and experience they gain during migration. Our data suggest that two domestic factors might have a significant impact on their migratory success - body weight and longevity of stay in nest. Early departure from the nest is strongly associated with migratory failure, so highlighting potential negative impact of late season disturbances in the vicinity of nests. Most successful birds left their nests late and started the southward migration straight from the nest. Typical migration consists of comparatively short bursts of flight days interspersed with longish foraging stops along their long journey - the longest one from our data exceeding 10,500 km one way. The most important factor affecting success of travel appears to be longevity of stay at the most important foraging stops rather than number of sites they explore. Those birds that made a backward migration visited most of the sites they had explored earlier, however, with different travel routes between the stops. None of one-year old birds did return to breeding grounds. Instead, they spent their second summer in suitable territories 1,000 – 2,000 km from their nests (in Turkey, Romania, Moldova, Ukraine). In all but one of those territories checked we found many more resting storks, mostly of similar age, along with other species of wading birds. In most cases these sites were not known for local ornithologists / conservationists as important bird gatherings. One of such locations in Romania may potentially be the most important summer roost of 2nd calendar year Black Storks from Eastern Europe, thus deserving high degree of attention from the conservation viewpoint. We discuss also other factors potentially affecting migration success, such as late vs. early brooding, weather conditions, role of predators and learning "en route".

France: National Natural Reserve of Orient Forest Lakes Is the Best Place for Black Storks in Stopover
Stéphane GAILLARD1 and * Paul BROSSAULT2
1Parc Naturel Régional de la forêt d’Orient
2 Forestiers du monde

Since 1974, Black Storks have stopped over on the Champagne lakes, during their post-nuptial migration, between July and October. They take advantage of the annual drop in the water level for finding food (fishes and frogs).
In order to follow the chronology of the post-breeding migration of the Black Stork, weekly and simultaneous counts take place during the period of the most intense migratory flow in the Champagne lakes (between early August and mid-October). This method of visual counting and identification of rings has taken place since 2001.
The Lakes of the Forêt d'Orient, in the heart of the Regional Natural Park of the Forêt d'Orient, is the only French place regularly used by such a large number of Black Storks in stopover and over such a long period, 10 to 16 weeks depending on the year.
Between 2001 and 2018, 70 ringed individuals were controlled in the National Natural Reserve of the Forêt d'Orient which has concentrated almost all the observations made in the lakes from the Aube area.
These birds come preferentially from Belgium and the Czech Republic, but also from Germany and Poland.
After more than 15 years of monitoring, the annual migration over the lakes of the Forêt d'Orient is estimated minimum between 150 and 200 individuals. There is an important place loyalty for some birds, such as two Czech storks, present every year for 12 years in the area.
The reserve and the large lakes therefore play a major role in France for pre-migratory grouping as well as for reading rings.

Wintering of the Black Stork in Doñana Natural Space and Surroundings Marshes, SW of Spain
Manuel MÁÑEZ, Luis GARCÍA, José Luis ARROYO, José Luis DEL VALLE, Rubén RODRÍGUEZ, Antonio MARTÍNEZ and Alfredo CHICO
Equipo de Seguimiento de Procesos Naturales, ICTS-RBD, Estación Biológica de Doñana, CSIC

This paper presents the results of the monitoring of the wintering population of the Black Stork since January 2000 in the Doñana Natural Space (DNS) and the rest of the marshes on the right bank of the Guadalquivir River. Moreover, the Brazo del Este and Isla Menor (left bank) were also surveyed.
There are news of the wintering of this species in the study area since the early eighties, reaching a few dozen birds, only on the right bank, until the end of the last century.
The data used have been extracted from the winter census of waterbirds that takes place in mid-January in the mentioned area. The figures range from a minimum of 52 individuals in 2001 to a maximum of 367 in 2012. Clearly, the wintering population shows an increasing trend, and the figures obtained year after year mean that the Guadalquivir Marshes are probably the most important overwintering area for the species in Europe.
If we break down the global census in three different areas (DNS except the small rice field zone within it, the rice fields and the rest of wetlands surveyed), the highest count every year, except one, is in the rice fields. In addition, it is in this habitat where the upward trend of the Black Stork wintering population is clearer. This may be mostly due to the huge amount of Red Swamp Crayfish Procambarus clarkia available in them, one of the main prey of the species during the winter season.

The Analysis of Black Stork Movements Based on Ringing, Ring Identifications and Tracking in Hungary
Enikő Anna TAMÁS and Béla KALOCSA MME BirdLife Hungary
Based on 2,366 ringed and 8 satellite transmitter-marked Black Storks in Hungary, furthermore numerous ring readings in the country, we provide information on migration, on habitat preference as stopover in connection with the water regime and some data on dispersion of the species.

Ringing of the Black Stork in the Czech Republic
1 Nature Conservation Agency of the Czech Republic, Kaplanova 1931/1, CZ 148 00 Prague, Czech Republic
2 Ceska Cermna 172, CZ 549 21 Ceska Cermna, Czech Republic

Since establishing the Bird Ringing Centre at the National Museum in Prague, 7,523 Black Storks have been banded in the Czech Republic in 1934 - 2018, predominantly as nestlings/pulli. Since 1994, the birds have also been marked by colour plastic rings with a code: 4,629 individuals (61.5 % of the total number) have been marked by this way. Approximately, during the last 10 years, for most of Black Storks ringed in the country, combination of plastic and metal rings has been applied. Using the colour rings, number of recoveries has dramatically been increasing: by 24 October 2018, more than 3,270 recoveries have been reported.
A significant part of the recoveries in abroad comes from West Europe, Hungary and Israel, while those from other areas/regions are rare. The oldest Black Stork from the Czech Republic was of 20 years old, the dispersal suggests high philopatry and fidelity in storks. On the other hand minority of Black Storks, approximately 10 % has used to breed hundreds of kilometres (up to 700 kilometres) from their place of birth. On the Czech Republic´s territory, between the meridian 140 and 160 E of Greenwich, migratory flyway/route divide was identified – South-westward via the Strait of Gibraltar, South-eastward via the Bosporus (The Strait of Istanbul) respectively. The ringing data show that during 41 years (1970-2011) beginning of the breeding season shifted by 5 days.

Wintering Black Storks Ciconia nigra in Iberian Peninsula:
Origins and Site Fidelity Obtained from Ringed Individuals

1 Rua João de Freitas Branco, n.º 38 – 2º Dto., 1500-359 Lisboa, Portugal
2 Department of Zoology and Physical Antropology, Faculty of Biology Sciences, Complutense University, 28040 Madrid, Spain
3 IUCN SSC Stork, Ibis and Spoonbill Specialist Group. Rue Mauverney 28, 1196 Gland, Switzerland
4 Rua , Arronches, Portugal

An increasing number of Black Storks Ciconia nigra remain to winter in a number of locations of Iberian Peninsula. The knowledge about the origin of these individuals is essential to assess eventual changes in migratory patterns and to determine other important aspects of Black Storks’ ecology such as longevity and site fidelity and also to access the conservation status and habitat requirements of these sites. All the available information on ring controls and recoveries was gathered from the Portuguese and Spanish ringing centres, from social media and dedicated websites. Directed efforts to control rings and count individuals were done by the authors in a number of winters at some of the main wintering sites.
The data collected shows that the wintering population is from both Iberian and Central European origin and that there has been an increase in the proportion of Central European ringed storks in the last decade. This proportion is much higher at newer regular wintering sites what suggests that there might be a change in the migratory strategy of the species with a larger number of individuals staying in Europe instead of migrating to Africa and those storks that are colonizing these new wintering sites are mostly from the non-Iberian population. Regardless of their origin, many individuals show a very high site fidelity and some use the same wintering area since their first winter. Conservation implications of colour ringing as a conservation tool are discussed.

Wintering Black Storks Ciconia nigra in Portugal:
Evolution of the Distribution, Habitat Preferences and Origin

1 Rua João de Freitas Branco, n.º 38 – 2º Dto., 1500-359 Lisboa, Portugal
2 Reserva Natural do Estuário do Tejo/ICNF, Avª. dos Combatentes da Grande Guerra, 1, 2890-015 Alcochete, Portugal

During the last two decades, an increasing number of Black Storks Ciconia nigra remain to winter in a wider number of locations of Iberian Peninsula. In a previous study, some environmental and geographical factors affecting the winter distribution of the Black Stork in Iberia were analysed. Data provided by an extensive count across Portugal and Spain during the winter 2012 – 2013 supported that Black Storks were more abundant in areas of high habitat suitability close to the migratory flyway and were absent or in reduced numbers in areas away from the migratory flyaway. These results were used to assess habitat suitability and to model the long-term evolution of the Iberian Peninsula as wintering ground for the Western and Central European population of Black Storks.
In the present work we compiled all the data available from wintering Black Storks in Portugal with the objectives of characterizing the evolution of occupancy area and habitat preferences and to evaluate the suitability of the model developed in the work mentioned before. The data collected shows that there has been an increase in numbers and occupancy area with several new regular wintering sites in the last decades and that the model predicted well these new settlements. The wintering sites in the late 1980s’ and 1990s’ were mostly rivers and small wetlands (mostly small reservoirs) but the newer sites are essentially large areas of rice field. Most of these areas are unprotected. Control of colour rings allowed identifying the origin of some individuals that are both from the Western and Central European population.

Wintering of Black Stork in France – the Sample of DIVA – CM32 a Black Stork Wintering in France, Tagged 3 Years Ago
Frederic CHAPALAIN (LPO France Birdlife – CRBPO), Nicolas GENDRE (LPO France Birdlife) and Antoine JORIS (Réserve Africaine de Sigean)
Black Stork breeds in France since 1973. The West European population is largely trans-Saharan migrant. A majority of individuals migrate through the Western European route through French territory crossing the passes of Pyrenees and after the Strait of Gibraltar. Wintering in the Iberian Peninsula began in the 1950s. More recently, Black Storks have started wintering in France, but remain relatively rare. In 2004, the number of wintering individuals was estimated to be few individuals. We can estimate between 30 and 40 Black Storks winter in France in 2018, mainly in the Mediterranean arc. Since 2010, a Black Stork nicknamed DIVA, banded when it was a chick at nest in Luxembourg by Patric Lorgé in 2008, is observed annually in winter at the zoological park of Sigean, the swamps of Narbonnais and the rice fields surroundings by Antoine Joris as well as observers of Aude Nature and LPO Aude. In the autumn of 2015, a partnership was established among the Réserve Africaine de Sigean, the CRBPO banding programme and the LPO France to equip DIVA with a GSM / GPS / UHF device to study its wintering and to locate its nesting site. We present here the monitoring of its wintering during three winters.

From Small Rivers to Large Rice Fields

«CM32, d'un petit ruisseau à une grande rizière» is a short film of 8 minutes and 50 seconds, initially made for the Réserve Africaine de Sigean (located in the department of Aude, Occitan region at the eastern end of the French Pyrenees). This short film tells the story of the monitoring of the Black Stork CM32 – DIVA-. It was ringed when it was a chick at nest in Luxembourg in 2008 by Patric Lorgé. Since 2010, she is observed annually in winter in the zoological park of Sigean, the swamps of Narbonnais and the surrounding paddy fields by Antoine Joris as well as observers of Aude Nature and LPO Aude. In autumn 2015, a scientific partnership was established between the Réserve Africaine de Sigean, the banding programme (CRBPO) and the LPO France to equip DIVA with a GSM / GPS / UHF device. The objective is to locate its nesting site and study its nesting and wintering home ranges. The reproduction of this bird is followed by the ONF in the department of Meuse. Telemetry monitoring of this French breeding bird wintering in France has been ongoing for 3 years.

Migration of Black-Stork in the main migration spots in South of France:
West Pyrenean pass and Gruissan

Jean-Paul URCUN (LPO Délégation territorial Aquitaine – Birdlife), Mathieu BOURGEOIS (LPO Aude), Frederic CHAPALAIN (LPO – Birdlife – CRBPO) and Nicolas GENDRE (LPO France / Birdlife)
The majority of Black Storks are trans-Saharan migrants in the Western European population. Most individuals migrate through the Western European route through French territory cross the Pyrenees over the Basque Country area (especially at Organbidexka pass) towards the Strait of Gibraltar. Others, however, take the Eastern route of the Pyrenees, and pass over the Roc de Conilhac Gruissan. The monitoring of these migration sites have been provided for many years by local ornithologists (LPO Aquitaine, GAN-NIK, Collective Lizarrieta, CPAL, LPO Aude, Collective Gruissan, among others). Reflecting the growth of the European population until 2012, the number of Black Storks counted seems to be stabilized since then. In 2018, 148 birds were observed by the East flyway (Roc de Conilhac in Gruissan) and 1 382 by the West flyway (901 at the Organbidexka pass, 437 at the Lindux Redoubt and 44 at Lizarrieta).

Ringing Results and Sexing Results in France, the Monitoring of Ringed Nestling Birds
Frederic CHAPALAIN (LPO France / Birdlife - CRBPO), Luc STRENNA (LPO Côte-d’Or - CRBPO), Nicolas GENDRE (LPO France / Birdlife) and Jean-Jacques BOUTTEAUX (ONF)
From 1995 to 2018, 966 young Black Storks of 302 different broods were banded at nest in 22 departments and 116 communes in France. 103 birds were caught flying. 580 individuals were sexed. This was only possible thanks to a considerable effort of the national Black Stork Network (NFB network, banding programme and volunteers of naturalist associations who actively contribute to the follow-up the species). As of 1 October 2018, 257 resighting marked birds were recorded in France. In total, 1,001 resighting data of birds (alive or dead) and 251 birds banded abroad were recorded again in France, with a total of 972 resighting data (alive or dead). A special effort has been made in recent years on reading ring’s codes of breeders. This has a particular interest in highlighting a geographical dispersion (distance).The results point out that males have higher geographical dispersion than females. Overall male individuals are more controlled than female individuals. Females, particularly nesting females, appear to have post-breeding dispersal and early autumnal migration than males.

Tracking Results in France, Home Range of Breeding Adults in France, Focus on the Nievre Region Programme
Frederic CHAPALAIN (LPO France/Birdlife – CRBPO), Nicolas GENDRE (LPO France/Birdlife), Annie CHAPALAIN (LPO Nièvre), Claude CHAPALAIN (LPO Nièvre), and Daniel DUPUY (LPO Nièvre)
The first tagged Black Stork with an ARGOS transmitter was 1998 in France. The main objective was to know the migration of the Black Storks from France. Now, the performance of current devices (GPS data every 2 minutes) allows much detailed studies of the home ranges of breeding adults. Since 2015, the LPO France and LPO Nièvre have joined a banding programme to study breeder (adult) Black Storks, in collaboration with different partners (DREAL, ONF, Sigean African Reserve, Regional Nature Parks, local associations, among others). In total, since 2015, 11 individuals have been equipped with Ecotone or Ornitela brand GSM / GPS tags. Thus, five birds including four breeding adults have been tagged in the department of Nièvre. Home ranges were determined by calculating the Kernel 95%. Depending on the sex, the years and the nesting phase (e.g. brooding, feeding) they vary from 9,000 Hectares to 26,000 Hectares. Within these core areas, there are usual feeding sites (small streams of watershed with species such as Cottus sp, ponds, pond tails, wet meadows with batrachians). Not only these small beacons make possible know the home ranges of the birds, but also to refine the knowledge of their movements and their behaviour during the reproduction period (no nocturnal movement, first early flight followed by a strong activity of fishing, greater displacements when the temperature increases, nocturnal resting places rarely in the immediate vicinity of the nest). One of the objectives of this monitoring is also to guide measures of restoration of ecological continuity carried by the managers of territory (regional natural parks, Natura 2000 site promotor, among other stakeholders).

Migration Strategies and Extremely High Mortality Rates of Satellite-Tracked Upper Silesian Black Storks Ciconia nigra
Joachim SIEKIERA, Piotr PROFUS, Tomasz BIWO and Artur SIEKIERA
Institute of Nature Conservation, al. Mickiewicza 33, PL – 31-120 Kraków

26 (18 males and eight females) from eight nests located in Opole Silesia (SW Poland) were equipped with GPS satellite transmitters (13 in 2017, and 13 in 2018). Fledglings left their nests for the first time between 12 July and 2 August (median = 18 July; n = 25). After 13–44 days (median = 27.5 days; n = 24) spent near the nests, they started to move away from their hatching place. Between 29 July and 29 September (median = 14 August; n =24), fledglings began to relocate in different directions in the process of post-breeding dispersal. Few individuals started migrating towards potential wintering areas. All fledglings (100%) with GPS satellite transmitters installed in 2017 were killed and not a single one survived a year.
One fledgling (almost capable of flying) died shortly before reaching the ability to fly – probably killed by a predator. Other seven birds died in Poland before deciding on the direction of migration. Two fledglings were killed (during post-breeding dispersal) by a strong windstorm in the northern part of the country, 403 and 445 km in a straight line from their parents’ nest. Two birds were found dead (with no visible signs of injury) 17 and 270 km also north of their hatching place. One fledgling was killed and eaten by a White-tailed Eagle Haliaeetus albicilla and another one was killed by a Northern Goshawk Accipiter gentilis. Probably the third fledgling was also killed by a predator. Two birds migrating along the south–eastern route were found dead under a 15 kV power line in Romania and Bulgaria (708 and 1105 km from the hatching site, respectively); they died a result of electrocution on unprotected electrical poles or in collision with overhead power lines. Two other individuals flew along the south–western route but only one of them crossed the Strait of Gibraltar and reached the environs of Ben Mansour in northern Morocco – 2,681 km in a straight line from its birthplace. This bird probably died here, because the last signal from its transmitter was received on 31 December 2017. Other bird stayed for a relatively long time in the Camarque nature reserve in southern France to overwinter but died on 3 March 2018 near Arles on a 110 kV high voltage traction seven months after the installation of the transmitter. One of the birds first chose the south–eastern migration route: it reached Austria and in the morning of 25 October 2017 started its migration from south–western Hungary, flew through Bosnia-Herzegovina, Croatia and the Adriatic and in the afternoon reached Torchialoro in southern Italy, where was most likely killed by man. On that day, the stork covered a distance of 743 km, including 445 km over the Adriatic, and in some sections of the migration route it travelled at a speed of up to 93 km/h.
In 2018, one bird out of 13 birds with GPS satellite transmitters died in the nest before its first flight, while another bird broke its wings shortly after leaving the nest and was placed in a shelter for animals. Two individuals – in Poland and in Hungary – were found dead under a 15 kV electric traction. One of the birds travels through Serbia and Albania to western Greece and Crete, where it made an unsuccessful attempt to fly over the Mediterranean Sea and disappeared there. In two other cases, the cause of death of young birds in Romania and Serbia remains unknown. On 5 November 2018, seven young black storks are still alive in France, Serbia, Greece (2 individuals), in the European part of Turkey and northern Israel (2 individuals).
Siblings commonly use different migration routes. Of the three young birds coming from one nest, each of them chose a different route of migration to wintering grounds. One of the fledglings has embarked on a migration to the south–west and is currently not far from Saint-Étienne in southern France, the second one is in western Greece and the third one – in the European part of Turkey. The number on the ring of the young bird, staying currently in France, was read in four places (9–12 October 2018) by local ornithologists during its flight through Switzerland.
During the day, the longest autumn migration flights took place over a distance of 141–743 km (median = 263 km; n = 22) and the highest recorded height at which young black storks were then observed was 4,480 m.
This high juvenile mortality rate during migration seems to be the main cause of the Black Stork disappearance in Upper Silesia in the past ten years.

Conference Plenary Discussion, Conclusions and Recommendations of the VII International Conference on Black Stork Ciconia nigra (Doñana National Park, Spain)
https://storkibisspoonbill.org/wp-conte ... ations.pdf

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Post by Anne7 » August 27th, 2019, 6:00 pm

About Metabolism and Thermoregulation in birds
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Post by Anne7 » August 29th, 2019, 4:29 pm

“Clearly, animals know more than we think, and think a great deal more than we know.”
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Post by Liz01 » October 17th, 2019, 7:01 am


Any member who wants to suggest alterations or additions to forum Rules should first consult with the Admin team.

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Post by Liz01 » October 28th, 2019, 12:32 pm

The role of corticosterone during the migration flight
Long-distance migration requires many physiological and behavioural adaptations such as changes in muscle enzyme activities, hyperphagia and night activity in otherwise day active migrants. During migration birds alternate between periods of stopover when fuel stores are built up and flight bouts when fuel stores are consumed. Migrants need to switch physiologically and behaviourally between these two opposite states. We investigated whether corticosterone, the most prevalent glucocorticoid in birds, is involved in the regulation of bird migration.

Most migrant birds do not fly in one flight bout from their breeding to some wintering grounds, but they alternate between flight and stopovers. During stopover, birds generally try to build up fuel stores, while during flight fuel stores are partly or completely consumed. Little is known about the hormonal regulation of the energy metabolism during migration and findings so far were often conflicting. During the last years the glucocorticoid hormone corticosterone was discussed as a candidate, which might orchestrate the energetic needs during migration.

During migratory flight, when birds are in a fasting state, slightly elevated baseline levels of corticosterone promote the mobilisation of the energy stores. A strong increase in corticosterone when fat reserves are near exhaustion triggers an increase in the catabolism of protein and probably a change in behaviour. During refuelling when birds are in a resorptive state slightly elevated corticosterone concentrations seem to support fuel deposition. Experiments suggest that this may be triggered by the geomagnetic field, indicating the position in relation to desert and ocean crossings.

project management
Susi Jenni-Eiermann, Lukas Jenni

https://www.vogelwarte.ch/en/projects/b ... -migration

Thank you pica! Now I have found the English version. i hope it works ! Yes- it works :laugh:
BTW: For me, the link led to the German version. I do not understand how he comes to Error 404 with you :puzzled:

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Post by pica » October 28th, 2019, 1:32 pm

Liz01 wrote:
October 28th, 2019, 12:32 pm
The role of corticosterone during the migration flight
liz, unfortunately your link drives to code 404 :nod:

here is the one:

https://www.vogelwarte.ch/en/projects/b ... -migration

under the article in german, there are other publications mentioned:
https://www.vogelwarte.ch/de/projekte/v ... er-zugzeit

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Post by Anne7 » July 15th, 2020, 12:10 pm

About scute patterns

Passerine foot-scutes
"... Bilateral asymmetry of individuals and individual uniqueness of details of patterns of foot-scutes are apparently characteristic for many bird species.The extent of individual variation is reminiscent of the well-known ones for human fingerprints, palms, soles, and toes...
The papillae are resilient and after indentation by weak pressures tend to regain their original shapes, as I have seen on thawed carcasses. Furthermore the firm attachment of papillae and scutes seemingly tends to prevent changes in their alignment, though presumably severe injuries or diseases might alter the appearance ...
... Little is known about the molting of either tarsal scutes or those on the feet. Jeffries(1883) reported such molting, but apparently the most detailed observations are the brief remarks of Gullion (1953) on the American Coot (Fulica americana). Neither these accounts nor my observations indicate that molting modifies the arrangement in scutellation..."
https://sora.unm.edu/sites/default/file ... -p0558.pdf

Scute Patterns as an Individual Identification Tool in an American Crocodile ( Crocodylus acutus ) Population on Coiba Island, Panama
Identification of individuals based on morphological patterns is a strategy used primarily in human forensics that has also been applied successfully in several wildlife scenarios. To date, no study has evaluated the potential of these techniques on American Crocodiles (Crocodylus acutus). We assessed whether the dorsal scute number and pattern of 110 American Crocodiles captured from the wild on Coiba Island, Panama could be used for individual recognition. We estimated scute variation using the number and position of scutes, testing both a binary and a coded assessment for scute presence and pattern, respectively. We analyzed scute patterns using 21 transverse scute lines (TSL) including the three most prominent scutes present on each side of the vertebral column axis. We found significant differences in the number of scutes per TSL and longitudinal scute lines (LSL) by individual. Based on both the binary and coded analyses, we identified all American Crocodiles assessed at the individual level, using only the first 13 and 10 TSL, respectively, in an anterior–posterior direction. This gave us a minimum probability of < 0.0003 based on the coded analysis and < 2.02 · 10-5 based on the binary analysis to find pattern repetition (one out of 3,333 and one out of 49,504 American Crocodiles have the most-common scute pattern, respectively). Because the C. acutus total population of Coiba Island has been estimated as no more than 1,000 individuals, we could use this individual identification pattern recognition method (IIPR) to identify every American Crocodile inhabiting this island.
https://www.researchgate.net/publicatio ... and_Panama
“Clearly, animals know more than we think, and think a great deal more than we know.”
— Irene Pepperberg

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