![puzzled :puzzled:](./images/smilies/puzzled.gif)
http://www.bbc.com/news/uk-scotland-tay ... l-27810357
I have heard of Peregrines keeping two nests,but for opsreys it seems unheard of.
![slap :slap:](./images/smilies/slap.gif)
Kukelke wrote:I don't know how to describe how shocked I am when I saw this:
https://www.facebook.com/media/set/?set ... 254&type=1 ...
A fledgling was apparently killed and pulled off the nest, today. It appears to be another fledgling who did the killing. I don't know what to think, other than there is something seriously wrong at that nest.macdoum wrote:Some disturbing behavior from the mother osprey at this nest.;
https://www.youtube.com/watch?v=Q_SuIbqFJjA
At Woods Hole oceanographic inst.
Video byscyllabub
Today she has been constantly aggressing her three chicks.![]()
![]()
(I don't know more)
Osprey nest on electric pole. Brandenburg State near Berlin:macdoum wrote:Is this the future for ospreys ?
http://www.rspb.org.uk/community/places ... r-you.aspx
there is a video:Chimega wrote: A fledgling was apparently killed and pulled off the nest, today. It appears to be another fledgling who did the killing. I don't know what to think, other than there is something seriously wrong at that nest.
English translation (by me):21-08-2014
Voor het eerst hebben visarenden nesten gebouwd in Nationaal Park de Biesbosch. En meteen twee ook. De zeearend heeft afgelopen jaar al met twee paartjes succesvol gebroed in de Biesbosch. De hoop is nu ook gevestigd op een broedgeval van de visarend.
Uniek
"Door de vele natuurontwikkelingsprojecten in het kader van Ruimte voor de Rivier is de Biesbosch de laatste jaren flink uitgebreid", aldus boswachter Thomas van der Es, boswachter in de Biesbosch. "Het zoetwatergetijdengebied is daardoor een nog aantrekkelijkere plek geworden als jacht-en broedgebied voor de visarend."
"Het is uniek dat de visarenden dit jaar de hele zomer in de Biesbosch verbleven. Normaal gebruiken ze Nederland als tussenstop op hun trekroute van hun zomergebieden in het noorden en oosten van Europa en de gebieden waar ze in de winter verblijven, zoals het Middellandse Zeegebied en Afrika."
Drie visarenden
Er zijn minimaal drie verschillende visarenden gezien in de Biesbosch deze zomer. Soms vliegend met flinke takken die gebruikt worden als nestmateriaal. In augustus werden de vermoedens bevestigd en vonden boswachters van Staatsbosbeheer een tweetal nesten in hoogspanningsmasten. Dit jaar zijn de nesten nog niet gebruikt, maar het zou kunnen dat de nesten gebouwd zijn om volgend jaar als broedplek te dienen. Voor zover bekend is er alleen in 2002 ook een nest gebouwd in de Oostvaardersplassen. Hierin is uiteindelijk niet succesvol gebroed.
Zomervogel
Nu de najaarstrek is aangevangen verblijven er meerdere visarenden in Nederland. Vaak verblijven de vogels enige tijd in visrijke gebieden, voordat ze weer doortrekken naar hun overwinteringsgebied in onder andere Afrika. Visarenden blijven tot halverwege oktober in Nederland. Visarenden keren weer terug in Nederland uit hun overwinteringsgebieden vanaf april.
Zeearend en visarend
Sinds 2012 broeden er zeearenden in Nationaal park de Biesbosch. In 2014 waren er zelfs twee succesvolle broedgevallen met een totaal van 4 jonge vogels. De visarend is een slag kleiner dan de ‘vliegende deur’ en heeft een vleugelspanwijdte van ruim anderhalve meter. Visarenden eten enkel vis en vangen die op spectaculaire wijze uit het water. Op hoogte van soms wel 30 meter hangt een visarend biddend boven het water en met een enorme duik pakt hij met zijn stevige klauwen grote (wit)vis. Zeearenden en visarenden zijn concurrenten van elkaar en het is dan ook de vraag of ze in de toekomst beide in Nationaal Park de Biesbosch kunnen broeden.
http://www.staatsbosbeheer.nl/Nieuws%20 ... bosch.aspx
In August and September many ospreys are about in the Biesbosch. "This year there were socalled 'oversummering' ospreys and they have puzzled together two nests," said forester Thomas van der Es of the Forestry Commission. "I don't think that this ever happened before."
The Osprey is in our country known as a transmigrant. The predominantly fish-eating birds of prey do not breed in the Netherlands, although occasionally there is a nest building attempt. The last time this happened was in July 2002. Back then employees of the State discovered a nest in the Oostvaardersplassen. There, a female was seen dragging with branches. Everyone looked forward to the following spring, but unfortunately the osprey couple was absent then. "As far as I can tell, ospreys have never done something like this in the Biesbosch before. Both nests which we recently found here are also the first for De Biesbosch. The Ospreys didn't build their sheds in trees, but on the cross sections of power pylons. "That situation is unique for the Netherlands, but in other countries it's a well known fact. For many years Ospreys have been building nests in power pylons in the Müritz National Park, a top-noth water area with numerous lakes in Mecklenburg-Vorpommern. However, the masts there are considerably lower. "Both nests in the Biesbosch apparently look like constructions of black crows, but when you get closer you'll see that they are much larger, a meter in diameter; in addition there are also long, thick branches woven in."
Nest baskets
"It's probably that one of the two osprey nests originally was a crow's nest, that is, ospreys at least used the existing crow's nest as a starting point and filled it with more branches. "Since ospreys like to linger in De Biesbosch, the Forestry Commission in May 2003 decided to urge the osprey to breed here. In order to lend the birds a helping hand aluminum nest baskets were placed in various power pylons. "In 'Polder the Turfzakken' you can clearly see the basket hanging in the power pylon, but the ospreys leave that basket alone, and rather build their nest at another place in the very same mast. About the continuation of these nests it's difficult to say anything. Will the exact same birds return to these locations? Are the nests still there next spring, or will the branches all be blown off the masts during the first tempestuous autumn storm?" Supposed that the osprey would settle permanently as a breeding bird here, how would the white tailed eagles react on this? Will they tolerate each other or fight each other to the death? "Indeed an interesting question, but let us first welcome the osprey as a breeding bird once again. That would be nice, and after that we'll see what happens", concludes Van der Es.
The picture below was made by Niels van Pelt, using digiscope:
I've written an email with a couple of questions to the authorities of the national park where the nests are discovered. Among them a question about a possible webcam. I'll keep you updated when I hear something.Ferenz wrote:Thanks, Kukelke for the information. Do you know whether there will be a osprey nest cam installed next season as we have one in Brandenburg-State near Berlin?
A study of Finnish Osprey Birgit.What's the use of satellite tracking, anyway?
It's a question that regularly crops up on the non-science forums and social media sites. Those who ask it often load the question with some opinion to the effect that “we already know where these birds spend the winter, so what is the point of continuing to track them?” But the birds themselves provide the answer to this...
Increasingly, ecological research is getting down to the fine details of animal behaviour: things that only advanced technologies – close-up video cameras and microphones, and high-resolution data gathering – can uncover. These days, and probably for the first time in history, we are beginning to study bird behaviour in the wild on the scales at which birds themselves operate. And the observations are revealing.
Osprey “Birgit” fledged from a nest in southern Finland in August 2014 and, as part of a programme run by the Natural History Museum of Finland, was fitted with a GSM datalogger / transmitter unit. She duly migrated south-west over the Baltic and decided to make a stopover near the Ijsselmeer in Holland. Birgit's “2nd generation” tracker unit is able to record her position, speed and altitude every two minutes, varying this sample rate automatically according to her level of activity.
Birgit found that the flat fields and canals of the Dutch polder were much to her liking, and began to hunt for fish there – probably the first time in her young life that she had done this. The detailed satellite tracking shows that Birgit has instinctively adopted the usual foraging strategy for an osprey. She has some favourite trees for roosting, but does not visit the same places every day to hunt for fish. Instead, Birgit has prospected over a corridor that is some 20km in length, from the towns of Lemmer in the north to beyond Emmeloord in the south.
The fact that even juvenile ospreys – though not the most effective hunters, due to their inexperience – do not repeatedly exploit a single food source is important information, and Birgit has provided confirmation of it. In an increasingly crowded world, people and wildlife can come into conflict, and one charge often levelled at ospreys by the recreational angling community is that they “eat all the fish and then move on, leaving none for us to catch.” But this is wrong, and the latest technological tools are helping conservationists to prove it.
Birgit's autumn sojourn in Holland is just as useful to us as it is (no doubt) to her.