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 Post subject: Estonian WTE nestings: Summaries
PostPosted: April 8th, 2013, 2:31 pm 
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INTRODUCTION

The life of the WTE*)-pair Linda and Sulev has been followed already in summers 2009 and 2010 when they successfully raised two eaglets in both summers. In the beginning of each breeding season an introduction to the nest camera and the nesting pair has been given in the Looduskalender’s WTE nest camera opening page. Also in the beginning of season 2011 a summary of breeding seasons 2009 and 2010 was given in the WTE nest forum.

Information about Linda and Sulev and their family life has been given over the years is scattered in various places both in Looduskalender and in the forum. The aim here is to collect this information in one place where it will be easily found. Firstly information on the nesting eagle pair and their nest site is summed up and some links for further information are given. Secondly a brief overview on the previous nesting seasons is presented. Linda and Sulev are old friends to some viewers who have followed their lives in these previous years. Hopefully this summary will serve both these earlier viewers as well as the more recent ones.

Finally the main aim of these Summary pages is to review briefly the daily events at the nest. Pictures will not be posted here except in special cases, as they can be found in the forum pages in abundances. A link to the beginning to each day’s notes in the forum pages will be given for to make it easier to find any specific day.
_____________________________________
*) For shortness an abbreviation WTE will be used for white-tailed sea eagle.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 8th, 2013, 2:48 pm 
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1. Linda and Sulev: the white-tailed sea eagles whose life is followed

Names Linda and Sulev were given to the eagles by the forumists in the first camera season in 2009. Linda was born in Alam-Pedja nature protection area in 1998, some 180 km inland*). She had one sibling in the year when she was born. She was ringed by Einar Tammur who gave her in the right ankle the Estonian country ring with blue over white stripes. On the left ankle Linda got a ring with white over black stripes, colours which signify the year of birth. The year ring carries her personal code H407, where letter H also is a symbol of the birth year.

The history of Sulev is unknown, because he has no rings.

More information about Linda and Sulev can be found in an article of White-Tailed Eagle Camera News (03.03.2013 - 14:51) What do we know about Linda and Sulev? by Urmas Sellis, here: http://www.looduskalender.ee/en/node/15997
More of Linda's origins can be read in Looduskalender White-tailed Eagles Camera News here: http://www.looduskalender.ee/en/node/4238
and here: http://www.looduskalender.ee/en/node/6771
____________________________________
*) The wild-boar feeding ground is situated near Alam-Pedja nature protection area, but outside it.

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Picture 1. Alam-Pedja nature protection area on a Google map.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 4:15 pm 
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Pictures of Linda

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Picture 2. Linda in the old nest on March 6th 2010. (Cropped from the Pontu picture http://pontu.eenet.ee/kotkas-2010/2010- ... -12-28.jpg)


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Picture 3. Linda in the old nest on March 11th 2010. (Cropped from the Pontu picture http://pontu.eenet.ee/kotkas-2010/2010- ... -08-23.jpg)


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a

Image
b
Picture 4 a, b. Linda photographed outside nesting period by Valeri Stšerbatõhh.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 4:15 pm 
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Pictures of Linda's rings

Linda wears the Estonian blue-over-white(or metal) country ring on her right ankle. The blue colour is not always clearly seen: in poor lighting it often looks just dark or black. On her left ankle she has a white(or metal)-over-black ring with her individual code H407. The colours and the letter H denote the year of ringing: 1998.


Image Image
a .................................................... b

Image Image
c .................................................... d

Pictures 5 a, b, c, d. Linda's rings in close-ups. Pictures are cropped from Pontu camera pictures taken on March 15th 2010 at at 08:18 (a), 08:19(b), and March 17th at 10:31 (c) and 10:32 (d). The white over black year ring is slightly damaged: there is a notch above the letter H (c, d).


Image

Picture 6. Linda photographed in flight so that identification is possible. On Linda's blue/white country ring there is number 356. (Photograph by Valeri Stšerbatõhh. Picture from LK-pages.)


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 4:16 pm 
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Pictures of Sulev

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Picture 7. Sulev in the old nest on March 5th 2010. (Cropped from the Pontu picture http://pontu.eenet.ee/kotkas-2010/2010- ... -10-52.jpg)


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Picture 8. Sulev's tailmarks are the only possible way to identify him in any way. This picture is a collage of pictures of Sulev's tail taken in spring 2010. The collage was made by Hali.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 4:16 pm 
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2. Nest location

The nest of the white-tailed sea eagles (WTE) Linda and Sulev is situated in Noarootsi, in Silma nature reserve in Western Estonia near Saunja bay. The present nest is in a pine near the top in boggy terrain near the sea shore. The Saunja bay can be seen from the nest so the hunting grounds are closer to the new nest than the old nest which is some 1.5 km to inland. The nearest house is at a distance of 400 m. This farm house is probably the home of the dog whose barking can be heard to the nest in some late windless evenings. Also the noise of traffic from the Haapsalu road can be heard at the nest on calm weather.

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Picture 9. Map of North-Western Estonia showing the position of Silma nature reserve. (Google map)

Link to the webpages of Silma nature reserve: http://www.visitestonia.com/en/silma-nature-reserve


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 7:39 pm 
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3. Links

The direct stream from the nest can be followed on the Looduskalender page here:
http://www.looduskalender.ee/en/node/15887

or directly on a web player here: http://pontu.eenet.ee/player/saunja.html

or for VLC-users here: rtsp://193.40.133.138:80/live/saunja

The WTE nesting season 2013 forum pages start here: viewtopic.php?f=18&t=535

On the first link, the Looduskalender link you will also find an introduction to the fifth nesting season of the white-tailed sea eagle (WTE) camera written by Urmas Sellis (Estonian Ornithological Society, ESTLAT- Eagles cross borders project).

The White-Tailed Eagle Camera News in Looduskalender can be found here:
http://www.looduskalender.ee/en/node/2906

In connection of the live camera there is also a camera which takes still pictures of the nest once every minute for the archives. This camera is called Pontu camera. A similar camera is operational at each EENET- bird's nest camera. The still pictures can be found in addresses which are of the following form:
*ttp://pontu.eenet.ee/saunja/2013-04-08/2013-04-08-08-36.jpg

Here the first letter h has been replaced with *, so that the address can be seen as whole. In the address above 'saunja' refers to the WTE nest. For other nests this part should be changed to for example with 'kure' for the black storks Tiina and Tiit's nest camera, or 'tooni' for the other black stork's nest which has in recent years been inhabited by lesser spotted eagles Tuuli and Remo. The date appears in the address twice (in the above example 2013-04-08 means April 8th 2013) and the time -08-36 means 36 minutes past 8 am. Editing the date and time will open the desired Pontu picture. Note that the date needs to be changed twice. If the picture is not found even for a seemingly valid address the time may be too early or too late: pictures are taken and stored only in the light time of the day.

Both cameras, the live and the Pontu camera switch off in darkness in order to save energy. Both work, however, in very low light levels so in the last and first pictures of the day almost nothing can be seen.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 7:39 pm 
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4. Setting up the camera system for nesting season 2013

The solar panels which supply energy for the camera system were set up near the nest by Urmas Sellis and Renno Nellis from Eagle Club in early December. The camera itself and the 44 kg batteries for storage of power provided by the solar panels were taken to the nest at another time. Urmas and Renno were accompanied on the first trip by reporter Ulvar Käärt from the newspaper Eesti Päevaleht and photographer Ilmar Saabas (Delphi).
An article of the trip was published in Eesti Päeväleht on Dec 10th 2012:
http://www.epl.ee/news/eesti/kotka-pilg ... d=65381840
Liis made a translation of the article:
viewtopic.php?p=188842#p188842

On the same day Urmas went to the white-tailed eagles' feeding ground to set up the camera system there as well. On the website of Delphi you can find a photogallery which contains pictures and a short video taken on this trip to both of these sites.
http://www.delfi.ee/news/paevauudised/s ... d=65384766

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Picture 10. Renno and Urmas carry cables and solar panels to the nest site. In the video Renno comments: "Palju parem vana pesa oli." (The old nest was much better.), but his opinion is not decisive. The eagles have chosen the nest site to their liking. (Picture by Ilmar Saabas)

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Picture 11. Solar panels were set up about 80 m from the nest tree on the side facing to South in a small forest opening. (Picture by Ilmar Saabas)

Urmas Sellis writes about the camera system in the WTE-nest introduction in the introduction to this season:
"This time the camera system is arranged so that when darkness falls, all power consumers are switched off, and switched on again when daylight returns. This allows a significant reduction of power use, and we will not need to risk disturbing the nest life of the eagles with battery replacements. The solar panels work well when they are not covered by snow and the sun shines. With increased day length we will be able to transmit throughout day and night."


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 7:39 pm 
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5. Some history of the Estonian WTE nest web camera

The eagles’ nest web camera started broadcasting in the internet on March 5th 2009 as a surprise to Looduskalender members. Renno Nellis gave some basic information about the nest a few days later, on March 9th in the forum (viewtopic.php?p=21995#p21995). He told that the nest was located in Western Estonia (in Silma nature reserve), about 2 km from the Baltic Sea coast. The nest site was about 40 km from eagles’ winter feeding place.

Renno had found the nest in spring 2007. One eagle pair was known to have been breeding in the area at least since 2005, so the nest had been built already in 2005 or even earlier. In 2007 and 2008 the eagle pair raised two eaglets in each summer. Renno wrote: “In 2007 both nestlings were ringed and one of them we saw at the winter feeding grounds 1.02.2009.

The eagles were named Linda (the female) and Sulev (the male) by the forumists.

Image

Picture 12. The first nest was built in an aspen (Populus tremula). Using Urmas (who climbing in the tree) as a meterstick one can estimate that the nest is about 20 m above the ground. (Picture taken from LK-pages).


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 7:40 pm 
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Season 2009

Both eagles were seen at the nest when the web camera started broadcasting on March 5th 2009 at 14:35. Sulev appears for the first time in the Pontu picture at 16:06, and Linda joins him at 16:37. The nest was already well furnished for nesting. Matings were captured in Pontu pictures on March 6th at 7:06 and March 7th at 8:44. The last observed mating was reported on the forum and took place on March 8th at 10:20.

Linda laid her first egg at 18:11 on March 10th about 56 hours after the last observed mating. The live camera was malfunctioning at that time so no-one managed to see the egg-laying live. Fortunately the saved video stream was good. The egg itself cannot be seen on the video but Linda’s behaviour indicates rather clearly that the egg came then. A video clip of the first egg-laying is here: http://www.youtube.com/watch?v=DB_hbBIv ... J1&index=3

The laying of the second egg must have taken place in the next evening at about 18:18, but it cannot be as clearly seen as the first one. Before 18:08 Linda seemed to be somewhat uncomfortable again, but after that she rolled an egg and relaxed. It was, however, impossible to see if there were two eggs in the nest. Video of this event can be seen here: http://www.youtube.com/watch?v=1_VVKrbT ... r&index=39

The first chick in the nest was observed on April 16th at 11:42, on the 38th day, about 37 days 18 hours after the first egg was laid. Two chicks were seen at the same time for the first time during a feeding on April 18th at about 8 am, i.e. on the 40th day, about 37 days 14 hours after the second egg was laid.

Eaglets were named Sulli and Kluti by the forumists. Eaglets were ringed at the age of 46 and 45 days on June 1st at 17:24. Estonian LK members were able to hear part of what Renno was saying at the nest over the sound of wind. He said that these chicks were the biggest he had ringed that summer so far (early nesting), and that based on foot measurements he thought that the other eaglet was a female and the other a male. The other eaglet (probably the bigger female Sulli) scolded Renno vigorously all through his visit. The other (male Kluti, the smaller eaglet) stood still like a statue in the same place where Renno had put him for 2 hours and 20 minutes after ringing (as seen in Pontu pictures). Sulev returned to the nest 22 hours and Linda 26 hours after ringing. Both had probably though been in the vicinity of the nest all the time.

Comments on the ringing on the forum begin here: viewtopic.php?p=39675#p39675
A video of the ringing can be found here: http://www.looduskalender.ee/en/node/4085 .


Other milestones in the lives of eaglets Sulli and Kluti in 2009
    • Walking at the age of 24 days (backing up to the rim of the nest to toilet is not taken into account here).
    • Standing in upright position and starting wing exercises at the age of about 33 - 36 days. Feet clearly off the nest first time at the age of 45 days.
    • Cutting and eating by oneself without parent’s help at the age of 46 days.
    • Sleeping in upright position at the age 48 days.
    • Taking a grip on surrounding branches began at the age of about 65 days.
    • First true branching (longer stay clearly out of the nest on a branch) at the age of 70 days.
    • First genuine eagle call at the age of 67 days.
    • Virgin flight probably not earlier than the age of about 71 days. After this data is missing for about 10 days due to an antenna failure.
    • Last feeding by a parent at the age of 91 days.
    • Sulev’s last visit at the nest was seen on August 7th (day 113 after hatching of the first chick). He brought a fish at 12:23 to the eaglets who were at home and left right away.
    • Linda came to the nest for the last time at 17:55 on September 20th( day 157). She had brought a fish and waited for an hour, calling for eaglets a few times. They didn’t show up and so she ate the fish herself and left at 19:29.
    • The last visit of an eaglet to the nest was seen on September 28th (day 168).

The transmission from the nest suffered from power failures (June 26th – 29th, August 15th – 19th, August 24th – September 1st, and during some shorter periods), and an antenna failure (June 30th – July 6th). The regular transmission from the nest was ended on October 8th at 18:45, but the camera was turned on once again on October 21st for a few hours during the dismantling of the camera system.


Image

Picture 13. Urmas Sellis on the ground with the camera on Oct 21st at 17:32 in one of the last Pontu pictures in season 2009.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: April 15th, 2013, 7:40 pm 
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Season 2010


The camera had some test runs in the winter well before the breeding season. Pontu pictures were saved during these runs but the transmission was not made public. In the beginning of the first test run on January 25th – February 3rd the nest was first covered with thick untouched snow. In the morning on February 3rd Linda and Sulev visited the nest together. During the next test periods on February 6th – 10th and on February 24th no eagles were recorded on Pontu pictures. Continuous transmission from the nest began on February 27th and it was announced on March 3rd.

Sulev came to the nest on March 1st with something to eat. Later on March 3rd, 4th, and 5th he made some visits to the nest, bringing sticks. Linda was seen on the nest on March 5th for the first time since the visit in February. On March 6th both were busy in building the nest. On the next day both stayed away, but from March 8th onwards they started regular nest restoration. First mating attempt was seen at the nest on March 8th at 10:02, and the next successful one on the next day on March 9th at 9:44. The last mating was seen on March 18th at 6:28.

Linda laid her first egg at 17:05 on March 21st about 82 hours after the last observed mating. The laying was witnessed live by a wide audience in contrast to the previous year. Both Linda and Sulev were busy arranging the nest in that afternoon.

Forum comments on the sighting of the first egg begin here: viewtopic.php?p=63774#p63774
A video clip of the first egg-laying is here: http://www.youtube.com/watch?feature=pl ... 6l81sW0FmY

The laying of the second egg must have taken place in the evening of March 23rd after 19:10, the time when the camera turned off for the night. Before that Linda was drooping and drowsing in the nest, and later she showed no signs of egg-laying discomfort. In the next morning she flew out at 6 when Sulev came to release her from nest duty.

The first chick was observed on April 28th at 13:07, on the 38th day, about 37 days 19 hours after first egg was laid. Two chicks were seen at the same time for the first time during a feeding on April 29th at about 7 pm (possibly already at about 5 pm), i.e. about 37 days after the second egg was most probably laid.

The eaglets were ringed at the ages of 30 and 29 days on May 28th at 21:36. The antenna in the forest had failed on May 12th and transmission had seized. The repair of the antenna was postponed so that it could be done on the same trip as ringing, and thus the ringing was done at a younger age of eaglets than on previous year. Renno gave the normal Estonian blue-over-white country rings on the right ankles of the eaglets. In 2010 the colours on the year ring were blue-over-metal which in practice look the same as colours of Estonian country rings. Individual codes on the year rings given to the eaglets were C525 (M791 on country ring) and C526 (M792 on the country ring). Later the forumists named the bigger female C525 Teele and the smaller male C526 was named Timmu. The eaglets lay silent and still in the bottom of the nest during the ringing. One of the eaglets got up sitting an hour after Renno and Urmas had left but soon it lay down again next to its sibling. Sulev returned to the nest 17 hours and Linda 36 hours after ringing. Both had probably been in the vicinity of the nest all the time. At least in the video recorded during the ringing the parent(s) can be heard making a lot of angry warning calls in the forest near the nest. The voices of the parents were also heard near the nest in the next morning.


Image

Picture 14. Eaglets in the nest minutes before ringing. (Photo Urmas Sellis)


Image

Picture 15. Renno on the nest. The web camera is attached to a branch on the right. (Photo Urmas Sellis)


Image

Picture 16. Renno showing Teele’s rings. (Photo Urmas Sellis)


Comments on the ringing on the forum begin here: viewtopic.php?p=71535#p71535
An EENET.EE-video of the ringing can be found here: http://www.youtube.com/watch?v=ZlIT2ilH ... e=youtu.be


Other milestones in the lives of Teele and Timmu in 2010
    • Camera began to be offline most of the time starting from day 13 (of first eaglet’s age) and continuously from day 15 due to antenna failure. The antenna was repaired and transmission continued starting from the evening of day 30. Observation of first time walking was missed.
    • Standing in upright position at the age of 31 days (maybe earlier; see above). Starting wing exercises at the age of 35 days. Feet clearly off the nest first time at the age of 56 days.
    • Cutting and eating by oneself without parent’s help at the age of 48 days.
    • Sleeping in upright position at the age of 59 days (probably already at the age 58 days).
    • Taking a grip on surrounding branches began at the age of about 58 days.
    • First true branching (longer stay clearly out of the nest on a branch) at the age of 72 days.
    • First genuine eagle call at the age of 50 days.
    • Timmu fell out of the nest in the evening of July 16th after a careless wing exercise. Renno went to the forest to see how he was doing and found him sitting in a nearby tree below the nest height. In the next morning Timmu returned to the nest, so he made his virgin flight at the age of about 79 days.
    • Last feeding by a parent at the age of 86 days. After this there were several long breaks in the transmission, so the data is very sporadic.
    • Sulev’s last visit at the nest was seen on August 24th (day 118 after hatching of the first chick). He brought a dark-feathered bird with grey webbed feet (probably a coot?) at 15:25 and left right away. Timmu was at home and ate the bird.
    • Linda came to the nest for the last time at 10:11 on August 26th (day 120). She brought a fish which was eaten by Teele who was at home. Linda stayed only few minutes.
    • The last visit of an eaglet to the nest was seen on September 2nd (day 127).

The transmission from the nest suffered from antenna failures during several long periods (May 11th – 28th = days 13-30, July 19th – 21st = days 82-83, July 26th – 27th = days 89-90, August 4th – 15th = days 98-109) and some shorter periods. The regular transmission from the nest was ended on September 3rd at 20:37.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: May 7th, 2013, 3:33 pm 
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Linda and Sulev

The camera started working on March 10th at 13:35, and the corresponding forum notes begin here: viewtopic.php?f=18&t=273
The nest was without snow and was decorated with plenty of fresh pine twigs so the start looked promising. On the next day (March 11th) an eagle without rings was seen flying by (16:04) and then sitting in the nest tree (16:28). Later at 18:25 some eagle calls were heard.

Next time eagles were seen at the nest on March 16th: Linda and Sulev came to arrange twigs at the nest between 11:21 – 12:32. They also sang together at the nest. This was repeated on the next day, March 17th between 8:50 – 11:05.

On March 19th Sulev brought a twig at 9:20 and stayed a few minutes. The next day, March 20th, was the only day when Sulev and Linda were seen working at the nest somewhat diligently. Sulev brought a twig at 10:29 and Linda came bringing another twig at 10:38. They arranged little the materials in the nest and then they sat silently together on a branch behind then nest till 11:35. The last sighting of Linda and Sulev was on March 27th at 15:57: an eagle who seemed to wear rings took off from the nest tree. After this neither was seen at the nest in season 2011.


Image

Picture 17. Linda and Sulev in nest construction work at 10:39 on March 20th 2011. (Pontu picture)


Buzzards

On April 11th at 16:11 a pair of buzzards (Buteo buteo) came to test how the nest would make their home. They brought twigs, arranged nest materials and sat on a branch next to the nest till 19:52. On the next morning the buzzards came back already at 8:44. Again they brought twigs and arranged nest materials, and stayed at the nest till 11:15. After that the buzzards were not seen staying at the nest anymore.

Comments, pictures and videos of their visit can be found here: viewtopic.php?p=96330#p96330.


Image

Picture 18. The buzzard couple investigating the suitability of the eagles’ nest for their purposes. (Pontu picture 16:15, April 11th 2011)


Mallard

Early in the morning of April 27th a duck was in the nest to the surprise of the viewers. Comments in forum about the duck begin here: viewtopic.php?p=98166#p98166 .

The duck was already in the nest in the dawn as can be seen in the first Pontu picture at 5:45 although it was very well hidden. At 9:12 the duck got up and left. At this point the blue rectangular spot on the wing surrounded by white stripes, the so-called wing-mirror, was seen. This made it possible to identify the species: the duck was a mallard (Anas platyrhynchos).

Image

Picture 19. The mallard leaving the nest at 9:12 on April 27th. (Pontu picture)


After this the mallard returned to the nest every morning near 7 am and left the nest a little after 9 am. On May 2nd (on the 6th day) the mallard plucked some down out of its breast and left at 11 am. On the next day it left even later, at 11:36. On the 8th day (May 4th) the mallard was seen rolling at least 3 eggs in the nest. On that day the mallard stayed even longer: it left at 14:56. If she had laid an egg each day there were 8 eggs altogether in the nest by this time.

In the evening of May 4th a young WTE flew to the nest at 19:31 and began to break and eat the mallard’s eggs one by one. A hooded crow followed the eagle just a few minutes later and scolded the eagle while it was devouring the eggs. The eagle was seen breaking and eating at least 8, maybe even 9 eggs. After its meal the eagle climbed on a branch behind the nest and remained there roosting overnight.

In the next morning the mallard returned to the nest at 9 am. It stood on the rim of the nest looking at the remains of its eggs for 20 minutes. Then it picked some pieces of eggshells and flew away. Six minutes later it returned, looked at the nest for about 2 and half minutes, picked one more eggshell and flew away. It was never seen at the nest any more.


After these events many different birds and animals were seen and heard around and at the nest, but none of them stayed for any longer period of time. The rest of the season was spent watching a clover growing on the nest.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: June 7th, 2013, 2:32 pm 
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Season 2012


The camera started working on February 17th. The first picture taken at 13:52 shows a thick layer of untouched snow on the nest. The notes of the season begin here: viewtopic.php?p=128638#p128638 .

Voices of two eagles were heard over the camera on March 9th at 7:44. Voices of a single eagle were heard on March 10th at 6:48 and on March 16th at 8:12, and later on April 27th four times between 10:53 and 10:59. After that no eagle voices were heard through the camera.

In March 2012 Renno found a new nest occupied by Linda and Sulev so it became obvious that they were to stay absent from the camera nest again this summer (WTE web-camera news April 15th 2012, http://www.looduskalender.ee/en/node/12994 ). A year later on Feb 18th 2013 Urmas wrote in the WTE web-camera news: “Linda and Sulev abandoned their old nest and moved closer to the sea. On this site the tree carrying the nest is of poorer quality. The eagles have had to rebuild their broken nest at least twice already, but they evidently like the view better than at the old nest, and it is closer to their hunting grounds.” This may mean that they have nested in the new site already in 2011. In summer 2012 Linda’s and Sulev’s two eaglets were ringed on the new nest.

The old nest would not, however, stay uninhabited this summer either. On April 9th at 12:22 a buzzard (Buteo buteo) was sitting on the big branch on the right side of the nest and soon another buzzard joined its company. (viewtopic.php?p=134446#p134446 )

Later that afternoon they were heard singing near the nest. After 5 pm then the buzzards began to bring twigs to the nest and more of their meowing singing was heard out of the camera view. In the next morning the buzzards were back on the nest. They began to work diligently on the nest every day since then and furnish it to their liking. Apparently they were planning to stay.

The topic’s name was changed to “Buzzard Nest Webcam Discussion - 2012 ESTLAT” on Apr 13th and a new thread was opened for it in the forum: viewtopic.php?f=18&t=398 .

The LK-news noted the new inhabitants of the WTE-nest on April 15th 2012: http://www.looduskalender.ee/en/node/12987


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Picture 20. The buzzard couple at the nest on Apr 14th at 11:16 (web camera screenshot by Bea). The grey male on the left and the dark brown female on the right.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: June 7th, 2013, 2:33 pm 
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The buzzards were not ringed but fortunately the colouring of their plumages was slightly different, so it was possible to identify them individually even when size comparison was not possible. As it is usual in birds of prey the female was bigger than the male. The plumage of the female was brown and darker than the male’s, and she had a “smiley”-pattern in the back of her head: three spots of light feathers. The lowest spot sometimes looked somewhat elongated sideways nearly as an arch so it looked like mouth (this spot/arch could not always be seen clearly). Above the lowest spot she had two light spots symmetrically near the top of her head which looked like false eyes. The pattern changed shape from time to time but there was always some light colour in the back of her head. The plumage of the male was lighter than the female’s and it was more or less uniformly grey. The colour difference was the basis of naming the birds. The brown female was named Pruuni as brown is pruun in Estonian, and the grey male was named Halli as grey is hall in Estonian.


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Picture 21. On the left the grey male Halli (web camera screenshot by ame on Apr 14th at 9:19), On the right the female Pruuni with the back of her head towards the camera (web camera screenshot by ame on Apr 26th at 7:43). Usually the colour difference was not as prominent as in this pair of pictures.

Matings were heard outside of camera view on Apr 18th at 7:39 and on Apr 27th at 13:03. Pruuni laid an egg on Apr 28 at 8:38. This egg remained their only egg though the average size of a buzzard’s clutch is 2-3 eggs. Urmas wrote on Apr 28th: “Actually I was almost sure that here will be no eggs, because it is quite late already for Buzzard to lay (more suitable time for LSE) and in Estonia we are predicting low voles density year now - that means no sense to make efforts to breed very seriously. But of course, some pairs are successful in spite of all that. Hopefully H&P also!

In literature the incubation time said to be 33 – 35 days for a single egg, so the expected date for hatching was May 30th – June 1st. (Reference “A Field Guide to the Nests, Eggs and Nestlings of European Birds with North Africa and Middle East” by Colin Harrison (Collins 1975, reprinted 1985 with revisions, 1988).

The sharing of incubation duty varies with buzzards from one pair to another. Sometimes the female incubates almost solely and the male releases her only occasionally so that she can go foraging on her own. In some pairs the duty is shared more evenly between the parents. Pruuni and Halli was a pair of the latter kind. Usually Pruuni stayed on the egg for the nights, but in the daytimes Halli incubated almost as much as her.

Like in most birds of prey it is also with buzzards that the male’s duty to provide food for the whole family. Urmas wrote that the vole densities in Estonia were predicted to be low in year 2012. Despite of this Halli very seldom failed to bring some prey to Pruuni when he came to release her from nest duty. Most often the prey was a small mammal (vole, mouse, shrew), but some frogs were also on the menu. The prevalence of voles and mice in the diet of buzzards has given rise to their name in many languages: mäusebussard (German), hiirihaukka (Finnish), musvåge (Danish), musvåk (Norvegian), all of which can be translated as mousehawk. An interesting exception is the Swedish name ormvråk which translates as snakehawk, which reveals a speciality in the buzzard’s menu.


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 Post subject: Re: Estonian WTE nestings: Summaries
PostPosted: June 7th, 2013, 2:34 pm 
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Everything seemed to go well to the end of term, except that jays were a regular nuisance at the nest. They came to bother the buzzards for the first time already before the egg was laid on Apr 14th. Since that jays came to rant and scold buzzards rather frequently.

The parents had done some changes of incubation turns so that the incubating parent left some time before the replacing one was in sight. On the 34th day of incubation on June 1st at 15:06 Halli got up quite calmly and took off with no hurry, leaving the egg alone in the nest. The temperature was about 10 degrees. Rain started about half an hour later. Halli returned at 19:29 after staying away for nearly 4 and half hours. It had rained almost all the time. Pruuni had left at 13:40 when she was released by the male, and she returned for change at 20:50.

If the egg was fertile and contained a nearly fully developed chick it had certainly become too cold and died while it was unsheltered in that weather that evening. It is also possible that the egg was not fertile and that the parents sensed it because they heard no egg-talk (chirping of the chick from inside the egg). No such voice could be heard over the camera (but it was rather noisy). Someone had written in the thread that the female’s plumage was not quite adult-like yet, so maybe she was too young to produce fertile eggs. The fact that there was only one egg may have been a result of the immaturity of the female or lack of nutrition (even though they did not seem to suffer from lack of food). Whatever the reason for the failure of the nesting was it will remain unknown.

June 4th onwards the female began to be absent from the nest. From the next day onwards both parents began to leave the egg alone for longer and longer times. Both parents were at the nest on June 6th in the evening, but the egg was left alone for the night. Also on the 7th both parents visited the nest in the morning. Neither of the parents was seen at the nest since that.

On June17th at 6:26 a pine marten came and took the egg away. It had visited the nest already on May 19th at 6:28 but then Pruuni chased it bravely away.

Camera stopped working on June 22nd in the evening and didn’t restart after that. On June 27th the LK news announced that the camera had closed for this season.


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