Estonian Eagle Owl Nest 2022, 2023

Estonian Eagle-Owl Nest

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juta
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Estonian Eagle Owl Nest 2022, 2023

Post by juta »

The Eurasian eagle-owl (Bubo bubo)

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It is one of the largest species of owl, and females can grow to a total length of 75 cm (30 in), with a wingspan of 188 cm (6 ft 2 in), with males being slightly smaller.
Eagle-owl is smaller than the golden eagle (Aquila chrysaetos), but larger than the snowy owl (Bubo scandiacus).
Eagle Owls are distributed sparsely through rocky areas but can potentially inhabit a wide range of habitats. They have been found in habitats as diverse as Northern coniferous forests and the edge of vast deserts.
The Eurasian Eagle Owl is largely nocturnal in activity, as are most owl species. The call of the Eagle Owl is a deep resonant ooh-hu with emphasis on the first syllable for the male, and a more high-pitched uh-Hu for the female. Each member of an Eagle Owl population can be identified by means of its vocalizations.
https://ebird.org/species/eueowl1

This eagle owl mainly feeds on small mammals voles, rats, mice, rabbits and hares. However, prey can be killed up to the size of both fully-grown foxes and marmots and young deer.The other significant group of prey for Eurasian Eagle Owls is other birds and almost any type of bird is potential prey. Common avian prey includes corvids, grouse, woodpeckers, herons and, especially near coastal areas, ducks, seabirds and geese.

This species usually nests on cliff ledges, crevices and caves. Occasionally, they may also take over a bird nest made by a large bird such as common raven (Corvus corax) or golden eagle. Laying generally begins in late winter, sometimes later. One clutch per year of 1-6 white eggs are laid, measuring 56-73mm x 44.2- 53mm (2.2- 2.9" x 1.7- 2.1") and weighing 75- 80 g (2.6- 2.8 oz). They are normally laid at 3 days intervals and are incubated by the female alone, starting from the first egg, for 31–36 days. During this time, she is fed at the nest by her mate.

More info
https://www.inaturalist.org/guide_taxa/21659

Eagle Owl in Estonia

The Eagle Owl is one of the most endangered bird species in Estonia. The population of 30-50 breeding pairs was estimated in 2019. It inhabits mostly the coastal areas of Estonia. In 2021, only four chicks were found in Estonian known nesting sites. Two out of four juveniles died before the winter.
Eagle owls are wintering in Estonia

Info about this nest in English: https://www.kotkas.ee/uudised/eagle-owl ... amera-2022

Link to the webcam will be found here https://www.youtube.com/channel/UCCvBXT ... Saqd19N0Sg or
www.youtube.com/kotkaklubi

Videos by Kotkaklubi

Male and female



Male

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Askja
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Post by Askja »

Summary of the Season 2023

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Eggs laid:
#1: 22.03.2023, 23:16
#2: 26.03.2023, 02:49
#3: 30.03.2023, before 01:41

Hatched:
#1: 25.04.2023 after 34 days
#2: 26.04.2023 after 31 days
#3: 30.04.2023 after 31 days

13.06.2023: The owlets were ringed; #2 got an additional ring-shaped radio tag. Urmas commented that all chicks were in good condition and well fed at the time of ringing. The two bigger ones weighed slightly over 2 kg and the third a bit below 2 kg.

Our three owlets on 13.06.2023 - on their last day together, just before they were ringed:

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Fledged:
#1: 13.06.2023, 14:39 age 49 days
#2: 13.06.2023, 22:53 age 48 days
#3: 24.06.2023, 02:51 age 55 days*
*While #1 and #2 tumbled from the branch at their first venturing out, unable to fly up again, #3 spent almost six days branching before tumbling to the ground.

There were no confirmed sightings of #1 after fledging. #2 has been seen several times in the vicinity, identified by the brown radio tag on its leg.

02.07.2023: #2 and #3 got transmitters fitted on their backs. Urmas commented that #1 could not be found, that #2 had put on weight during the previous 19 days (+700g) but #3's body weight was 100g less than before.

#3 stayed in the vicinity of the nest site and was often visible on the webcam. After July 6th watchers felt that its condition was deteriorating from lack of food. It seemed also to suffer from an affection of its eyes. It began to return to the nest, where one food delivery by a parent could be seen. Also, some additional food had been provided by humans.

Comparison: #3 on July 4th and July 16th

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19.07.2023: The youngest owlet #3 was seen for the last time on webcam when it flew away from the nest box.

Updates:

August 2023: Unfortunately, even though two owlets have transmitters, we have never seen a single word of update about them after they went out of view. We don't know whether they move as expected, or if they're even still alive.

03.08. - 14.08.2023 Hanna, and later Hugo, returned to the nest and displayed a behaviour unusual for this time of year - rather like courtship (in hindsight, Urmas commented it would have been a sign that the chicks have perished).

07. or 09.08.2023 Hugo was last seen on camera.
13. or 14.08.2023 Hanna was last seen on camera.
20.08.2023 Hugo and Hanna have been heard for the last time on camera.

14.08.2023 Some news reached us via YT chatters. I put this here for lack of an official source:
Mari-Liis Kasesalu (YT-chat):
"... Aarne Tuule (executive board member of Kotkaklubi) wrote me back about owlets. #2 and #3 got GPS transmitters. After ringing #2 moved close by nest about 70 meters, then it discovered a forest. But the forest doesn't provide much sunlight, so gps solar battery died. After 23.07. there is no information about #2. Kotkaklubi hopes that the batteries are dead. If there is no information in the future, they have to go there and search for #2.
Our Princess Pancake #3 is not alive anymore, it passed away after it flew away from the nest… They don’t know the exact reason for death. Currently, #3 is in the Estonian University of Life Sciences, where veterinarian Madis Leivits can take samples and know the reason for death."

24.08.2023 Update by Urmas: He said, this morning vet Madis had checked the forest for owls and transmitter. First he found several remains of prey but no fresh ones. Later on, "the remains of both chicks were found, not far of each other, as well as transmitter. Remains were too old to say something about reason, only feathers and bones. According the prey remains Madis did not see lack of food, rather something else was the reason of death. He will try, if from bones it is possible to determine bird flu. Rather it could be not possible. Smallest chick is still in fridge, not analysed by now."

This is the end of this season. Our pair of adult owls have made a great effort and raised three beautiful owlets. The owlets fledged, still healthy. But then an unknown disease took all three of them away. Hopefully, the cause of death can be determined... perhaps further deaths of these wonderful birds can be prevented in the coming years.
“Animals, like us, are living souls. They are not things. They are not objects. Neither are they human. Yet they mourn. They love. They dance. They suffer. They know the peaks and chasms of being.” (G. Kowalski) Caveat: Apart from this remarkable sentence I do not agree with his philosophies.
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Post by Askja »

Here a bunch of studies on Eurasian eagle owls. Unfortunately, many of them are in German; much research has been done there in the last ten years. They usually have an abstract in English. Generally, research is very scarce. Most works deal with habitats, the qualities of nesting sites etc., rarely with the owls themselves, their behaviour and welfare.

🦉 General

- Moult pattern of primaries and secondaries in Eagle Owls Bubo bubo (2020, German)
- Dusk vocalization of Eurasian Eagle-owls Bubo bubo 2014-2018 under mid-European conditions
- Dusk vocalization behaviour of Eagle Owls (Bubo bubo) - I. Comparison of autumn and pre-laying vocal activity (2016, German)
- Factors affecting the vocal behaviour of Eagle Owl Bubo bubo: Effects of sex and territorial status (2002)
- On the life history of a reintroduced population of eagle owls (Bubo bubo) (~1990?)

🐀 Prey & Diet

- Food supply as a limiting factor for the Eagle Owl Bubo bubo in the Eifel/Germany? (2005, German)
- The Eurasian eagle-owl (Bubo bubo) diet in the Orava Region (N Slovakia) (2010)
- The Eurasian eagle-owl (Bubo bubo) diet in the Trøndelag region (Central Norway) (2016)

🥚 Reproduction

- Direct insights into the undisturbed behaviour of Eagle Owls at their nesting site - ... Part I. Precourting and courting periods (2017, German)
- Direct insights into the undisturbed behaviour of Eagle Owls ... - Part II: Activities and behaviours at the nest site during the egg laying and incubation period (2017, German)
- Direct insights into the undisturbed behaviour of Eagle Owls at their nest site - ... Part III: Chick rearing period (2020, German)
- Prey delivery and feeding behaviours of Eagle Owls Bubo bubo ... in 2015 during the chick rearing period (2020, German)
- Development of chicks and predispersal behaviour of young in the Eagle Owl Bubo bubo (2004)

🏞️ Environment

- Why do Eagle Owls change their nesting site? (2022, German)
- The contribution of non-protected areas to the conservation of Eurasian Eagle-owls in Mediterranean ecosystems (2017)
- Factors that influence mercury concentrations in nestling Eagle Owls (Bubo bubo) (2014)
- Wind Farms and Power Lines Have Negative Effects on Territory Occupancy in Eurasian Eagle Owls (Bubo bubo) (2022)

8-) Recommended Websites

- Brodowski-Fotografie/Eagle Owls (articles & photos, German)
- The Owl Pages
“Animals, like us, are living souls. They are not things. They are not objects. Neither are they human. Yet they mourn. They love. They dance. They suffer. They know the peaks and chasms of being.” (G. Kowalski) Caveat: Apart from this remarkable sentence I do not agree with his philosophies.
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Post by Liz01 »

Juta :loveshower: thank you very much for opening the topic. :2thumbsup: A eagle owl! What a big surprise :innocent:

14:54 visit by the male
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Post by Liz01 »

16:47 arrival
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16:50 off again
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Post by Polly »

Well that's great!
When the Estonian Goshawk camera was in the start-up phase, images of this nest suddenly started streaming.
Loved the atmosphere and appearance...also thought of owls. But I didn't expect Uhus.
Yes great! Now online. :thumbs:
Some hearts will beat faster.

Nice introduction @juta ... clear, concise and comforting. Thanks! :innocent:

And thanks @Liz for the first nice impressions. :2thumbsup:

I need a third tablet...
"Throw your heart across the river and swim after it."
Indian proverb
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Post by Polly »

It is interesting, if disturbing, to read that eagle owls are also critically endangered in Estonia (like Latvia).
Oddly enough, the landscape is portrayed as paradise - and animals cannot maintain their kind here.

Let's remember Bubo's nest... I will never forget this time.

Here in Schleswig Holstein we are experiencing an upward trend, albeit slowly and not without bad actions (hunting, poisoning - also in our village).

Let's keep our fingers crossed that owlets are allowed to thrive here and get a chance to grow old.
"Throw your heart across the river and swim after it."
Indian proverb
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Post by Liz01 »

March 22

Good Morning everyone :hi:

1:23 one of them came home :laugh:
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is preparing the nest
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1:27 flew off
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Post by Liz01 »

1:34 another visit
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1:37
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Post by Liz01 »

14:41:25 White tailed eagle is calling (Andra) It sounds like a female .. far away

16:17:23 visit by the male! he is calling
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Post by Liz01 »

16:21 he is hooting :D
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off he goes
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video soon. what a beautiful eagle owl :innocent:
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Post by Liz01 »

17:13 they are talking to each other. She sounds cute :innocent:
17:13 Male came in and is hooting
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what a beauty he is :innocent:
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Post by Liz01 »

17:15 he flew to the left and is hooting
17:38 he is hooting , she replies :innocent:

17:39 he came home
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17:41 he flew out
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Post by hahe_ »

17:13:55

The Owl is back in the nest :shake:

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Post by Liz01 »

18:12 male is back.. he is hooting
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18:14 he flew out again
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Post by Biker »

hello, everyone!

arrival of the male

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*Please don't feed the trolls!*
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Post by Biker »

22:00

he flies off
*Please don't feed the trolls!*
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Post by IceAge »

March 23.

Hello,

03:15
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*Only two things are infinite, the universe and human stupidity, and I’m not sure about the former.* Albert Einstein
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Post by Biker »

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16:13
takeoff
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IceAge :wave:
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Post by hahe_ »

17:33 Male comes home

Working and digging the nest bowl :rolleyes:

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