Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area
Regular monitoring of breeding population abundance and environmental factors related to the nesting habitat has proven fundamental for seabird conservation. Harmony Point (Nelson Island) is an Antarctic Specially Protected Area (ASPA) designated to manage and protect the high biological value of se...
Published in: | Diversity |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
MDPI AG
2023
|
Subjects: | |
Online Access: | https://doi.org/10.3390/d15050638 https://doaj.org/article/5829966758f6490ba54090eea285f3a0 |
id |
ftdoajarticles:oai:doaj.org/article:5829966758f6490ba54090eea285f3a0 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:5829966758f6490ba54090eea285f3a0 2023-06-11T04:05:34+02:00 Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area Francisco Santa Cruz Lucas Krüger 2023-05-01T00:00:00Z https://doi.org/10.3390/d15050638 https://doaj.org/article/5829966758f6490ba54090eea285f3a0 EN eng MDPI AG https://www.mdpi.com/1424-2818/15/5/638 https://doaj.org/toc/1424-2818 doi:10.3390/d15050638 1424-2818 https://doaj.org/article/5829966758f6490ba54090eea285f3a0 Diversity, Vol 15, Iss 638, p 638 (2023) Catharacta brown skua south polar skua habitat suitability South Shetland islands topography Biology (General) QH301-705.5 article 2023 ftdoajarticles https://doi.org/10.3390/d15050638 2023-05-28T00:34:15Z Regular monitoring of breeding population abundance and environmental factors related to the nesting habitat has proven fundamental for seabird conservation. Harmony Point (Nelson Island) is an Antarctic Specially Protected Area (ASPA) designated to manage and protect the high biological value of seabirds’ richness and abundance. However, due to the remote location of their breeding sites, many species lack updated population counts. Skuas ( Catharacta sp.) exhibited a two-decade gap since the last census was conducted in Harmony Point. The abundance and spatial distribution of the nests of skuas were studied during the austral summer of 2019/2020. Through an exhaustive search, we counted and mapped active nests. Nesting habitat was assessed by the use of an unmanned aerial vehicle to take aerial pictures and build an orthomosaic image to determine vegetation in the area. Additionally, a digital elevation model was built to calculate a series of geomorphological-related variables. Suitability models were used to estimate the importance of variables to the nesting of skuas. A total of 71 brown skua ( Catharacta antarctica ) and 3 south polar skua ( C. maccormicki ) nests were counted. Two of the seven variables (terrain slope and vegetation cover) accounted for 57.5% ± 14.1% of the models’ variability; sun radiation incidence, and wind shielding were of secondary importance. Water flow accumulation, distance from penguin colonies, and terrain elevation were the least important variables. Skuas selected for nesting flat terrains (slope < 10°) with a vegetation cover of above 20%, slightly higher sun incidence (270 to 280 kW/h), and intermediary windshielding (45% to 55% of exposition). Considering previous estimates, the skua species at Harmony Point has kept an apparently stable population size over the last 25 years. However, expected changes in nesting habitat availability, i.e., increased snow-free area, increased wind intensity, changes in vegetation cover, and reduction of penguin populations, might ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Brown Skua Nelson Island South Shetland Islands Directory of Open Access Journals: DOAJ Articles Antarctic Austral Harmony Point ENVELOPE(-59.240,-59.240,-62.305,-62.305) Nelson Island ENVELOPE(-59.050,-59.050,-62.300,-62.300) South Shetland Islands Diversity 15 5 638 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Catharacta brown skua south polar skua habitat suitability South Shetland islands topography Biology (General) QH301-705.5 |
spellingShingle |
Catharacta brown skua south polar skua habitat suitability South Shetland islands topography Biology (General) QH301-705.5 Francisco Santa Cruz Lucas Krüger Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
topic_facet |
Catharacta brown skua south polar skua habitat suitability South Shetland islands topography Biology (General) QH301-705.5 |
description |
Regular monitoring of breeding population abundance and environmental factors related to the nesting habitat has proven fundamental for seabird conservation. Harmony Point (Nelson Island) is an Antarctic Specially Protected Area (ASPA) designated to manage and protect the high biological value of seabirds’ richness and abundance. However, due to the remote location of their breeding sites, many species lack updated population counts. Skuas ( Catharacta sp.) exhibited a two-decade gap since the last census was conducted in Harmony Point. The abundance and spatial distribution of the nests of skuas were studied during the austral summer of 2019/2020. Through an exhaustive search, we counted and mapped active nests. Nesting habitat was assessed by the use of an unmanned aerial vehicle to take aerial pictures and build an orthomosaic image to determine vegetation in the area. Additionally, a digital elevation model was built to calculate a series of geomorphological-related variables. Suitability models were used to estimate the importance of variables to the nesting of skuas. A total of 71 brown skua ( Catharacta antarctica ) and 3 south polar skua ( C. maccormicki ) nests were counted. Two of the seven variables (terrain slope and vegetation cover) accounted for 57.5% ± 14.1% of the models’ variability; sun radiation incidence, and wind shielding were of secondary importance. Water flow accumulation, distance from penguin colonies, and terrain elevation were the least important variables. Skuas selected for nesting flat terrains (slope < 10°) with a vegetation cover of above 20%, slightly higher sun incidence (270 to 280 kW/h), and intermediary windshielding (45% to 55% of exposition). Considering previous estimates, the skua species at Harmony Point has kept an apparently stable population size over the last 25 years. However, expected changes in nesting habitat availability, i.e., increased snow-free area, increased wind intensity, changes in vegetation cover, and reduction of penguin populations, might ... |
format |
Article in Journal/Newspaper |
author |
Francisco Santa Cruz Lucas Krüger |
author_facet |
Francisco Santa Cruz Lucas Krüger |
author_sort |
Francisco Santa Cruz |
title |
Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
title_short |
Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
title_full |
Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
title_fullStr |
Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
title_full_unstemmed |
Breeding Population and Nesting Habitat of Skuas in the Harmony Point Antarctic Specially Protected Area |
title_sort |
breeding population and nesting habitat of skuas in the harmony point antarctic specially protected area |
publisher |
MDPI AG |
publishDate |
2023 |
url |
https://doi.org/10.3390/d15050638 https://doaj.org/article/5829966758f6490ba54090eea285f3a0 |
long_lat |
ENVELOPE(-59.240,-59.240,-62.305,-62.305) ENVELOPE(-59.050,-59.050,-62.300,-62.300) |
geographic |
Antarctic Austral Harmony Point Nelson Island South Shetland Islands |
geographic_facet |
Antarctic Austral Harmony Point Nelson Island South Shetland Islands |
genre |
Antarc* Antarctic Antarctica Brown Skua Nelson Island South Shetland Islands |
genre_facet |
Antarc* Antarctic Antarctica Brown Skua Nelson Island South Shetland Islands |
op_source |
Diversity, Vol 15, Iss 638, p 638 (2023) |
op_relation |
https://www.mdpi.com/1424-2818/15/5/638 https://doaj.org/toc/1424-2818 doi:10.3390/d15050638 1424-2818 https://doaj.org/article/5829966758f6490ba54090eea285f3a0 |
op_doi |
https://doi.org/10.3390/d15050638 |
container_title |
Diversity |
container_volume |
15 |
container_issue |
5 |
container_start_page |
638 |
_version_ |
1768377113937707008 |