Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015.
In early summer 2015 a super peak of lemmings (Lemmus sibiricus) appeared on Beliy Island north of Yamal peninsula, Russia (73o19’N, 70o15’E). Considerable numbers of Snowy Owls (Bubo scandiacus) were present, possibly as a result of the abundance of lemmings. On 7, 9, 13, and 15 July a total of 69....
Main Authors: | , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Portuguese Society for the Study of Birds (C.E.M.P.A.)
2021
|
Subjects: | |
Online Access: | https://hdl.handle.net/11250/3133099 https://www.airo-spea.com/copy-of-archive |
id |
ftagderuniv:oai:uia.brage.unit.no:11250/3133099 |
---|---|
record_format |
openpolar |
spelling |
ftagderuniv:oai:uia.brage.unit.no:11250/3133099 2024-06-23T07:51:52+00:00 Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. Solheim, Roar Sokolov, Aleksandr 2021 application/pdf https://hdl.handle.net/11250/3133099 https://www.airo-spea.com/copy-of-archive eng eng Portuguese Society for the Study of Birds (C.E.M.P.A.) Solheim, R. & Sokolov, A. (2021). Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. AIRO, 28 (1), 432-441. urn:issn:0871-6595 https://hdl.handle.net/11250/3133099 https://www.airo-spea.com/copy-of-archive cristin:1924850 © 2021 The Author(s) 432-441 28 AIRO 1 VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Peer reviewed Journal article 2021 ftagderuniv 2024-06-11T14:22:41Z In early summer 2015 a super peak of lemmings (Lemmus sibiricus) appeared on Beliy Island north of Yamal peninsula, Russia (73o19’N, 70o15’E). Considerable numbers of Snowy Owls (Bubo scandiacus) were present, possibly as a result of the abundance of lemmings. On 7, 9, 13, and 15 July a total of 69.7 km was covered on foot. Snowy owls were approached and 344 images of perching and flying birds were captured. At most 89 individual Snowy Owls were seen from one vantage point. Images were sorted by number, time and date recorded on the image files. Images suitable to sex and age the owls were treated in Photoshop to enhance details of molt and bar patterns in wings. The birds were aged analyzing molt patterns, and individuals were recognized by bar and molt patterns in their wings. Eleven males and 14 females were aged, of which 14 (56%) were second calendar year (2CY) birds hatched in 2014. Six owls were in their second or third wing feather molt, thus classified as 3CY-4CY birds, while only five were birds with no juvenile flight feathers left (5CY+). Several individuals only photographed perching on the ground appeared to be juvenile 2CY birds, but these were not included in the sample due to lower certainty of identifying individuals and aging perched birds from images. Although two nesting pairs were recorded, the majority of the Snowy Owls on Beliy Island in July 2015 were young, presumably non-breeding birds. This study shows that photographying as many Snowy Owls as possible during an irruption may reveal the age and sex distribution of the birds present. publishedVersion Article in Journal/Newspaper Bubo scandiacus Lemmus sibiricus Yamal Peninsula Unvieristy of Agder: AURA Yamal Peninsula ENVELOPE(69.873,69.873,70.816,70.816) |
institution |
Open Polar |
collection |
Unvieristy of Agder: AURA |
op_collection_id |
ftagderuniv |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 Solheim, Roar Sokolov, Aleksandr Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480 |
description |
In early summer 2015 a super peak of lemmings (Lemmus sibiricus) appeared on Beliy Island north of Yamal peninsula, Russia (73o19’N, 70o15’E). Considerable numbers of Snowy Owls (Bubo scandiacus) were present, possibly as a result of the abundance of lemmings. On 7, 9, 13, and 15 July a total of 69.7 km was covered on foot. Snowy owls were approached and 344 images of perching and flying birds were captured. At most 89 individual Snowy Owls were seen from one vantage point. Images were sorted by number, time and date recorded on the image files. Images suitable to sex and age the owls were treated in Photoshop to enhance details of molt and bar patterns in wings. The birds were aged analyzing molt patterns, and individuals were recognized by bar and molt patterns in their wings. Eleven males and 14 females were aged, of which 14 (56%) were second calendar year (2CY) birds hatched in 2014. Six owls were in their second or third wing feather molt, thus classified as 3CY-4CY birds, while only five were birds with no juvenile flight feathers left (5CY+). Several individuals only photographed perching on the ground appeared to be juvenile 2CY birds, but these were not included in the sample due to lower certainty of identifying individuals and aging perched birds from images. Although two nesting pairs were recorded, the majority of the Snowy Owls on Beliy Island in July 2015 were young, presumably non-breeding birds. This study shows that photographying as many Snowy Owls as possible during an irruption may reveal the age and sex distribution of the birds present. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Solheim, Roar Sokolov, Aleksandr |
author_facet |
Solheim, Roar Sokolov, Aleksandr |
author_sort |
Solheim, Roar |
title |
Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
title_short |
Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
title_full |
Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
title_fullStr |
Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
title_full_unstemmed |
Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. |
title_sort |
age and sex of snowy owls (bubo scandiacus) during summer irruption on beliy island, yamal in 2015. |
publisher |
Portuguese Society for the Study of Birds (C.E.M.P.A.) |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/3133099 https://www.airo-spea.com/copy-of-archive |
long_lat |
ENVELOPE(69.873,69.873,70.816,70.816) |
geographic |
Yamal Peninsula |
geographic_facet |
Yamal Peninsula |
genre |
Bubo scandiacus Lemmus sibiricus Yamal Peninsula |
genre_facet |
Bubo scandiacus Lemmus sibiricus Yamal Peninsula |
op_source |
432-441 28 AIRO 1 |
op_relation |
Solheim, R. & Sokolov, A. (2021). Age and sex of Snowy Owls (Bubo scandiacus) during summer irruption on Beliy Island, Yamal in 2015. AIRO, 28 (1), 432-441. urn:issn:0871-6595 https://hdl.handle.net/11250/3133099 https://www.airo-spea.com/copy-of-archive cristin:1924850 |
op_rights |
© 2021 The Author(s) |
_version_ |
1802643004377268224 |