Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska
We estimated first-year and adult survival of Black Brant (Branta bernicla nigricans) from the Yukon—Kuskokwim Delta, Alaska, to assess (1) the role that first-year survival plays in declining recruitment and in the local breeding population's decline since the early 1980s and (2) the potential...
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American Ornithological Society
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ftbioone:10.1525/cond.2011.100218 2023-07-30T04:02:43+02:00 Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska James S. Sedinger Christopher A. Nicolai James S. Sedinger Christopher A. Nicolai world 2011-08-01 text/HTML https://doi.org/10.1525/cond.2011.100218 en eng American Ornithological Society doi:10.1525/cond.2011.100218 All rights reserved. https://doi.org/10.1525/cond.2011.100218 Text 2011 ftbioone https://doi.org/10.1525/cond.2011.100218 2023-07-09T09:23:43Z We estimated first-year and adult survival of Black Brant (Branta bernicla nigricans) from the Yukon—Kuskokwim Delta, Alaska, to assess (1) the role that first-year survival plays in declining recruitment and in the local breeding population's decline since the early 1980s and (2) the potential role of subsistence harvest in declining first-year survival. We used band-recovery models in program Mark to estimate band-recovery rates and annual survival from 1986 to 2007. The only models of band recoveries that received support contained annual variation and an additive effect of sex on band-recovery rates. The two best-supported models of annual survival differentiated between first-year and older Black Brant. The best-supported model (Akaike weight = 0.69) included a linear trend in first-year survival, while the second best-supported model (Akaike weight = 0.20) included an effect of mean gosling mass on first-year survival. Band-recovery rates corresponded to harvest rates of ∼1%, indicating that during the study period harvest was not demographically important. Adult survival was comparable (0.87) to that from other studies of this population, while first-year survival declined from 0.46 in 1986 to 0.24 in 2007. The trend of decline in first-year survival represented the effects of variation in conditions for goslings' growth in the breeding area combined with unknown effects on migration and in the wintering areas. Declining first-year survival is an important contributor to decline in the local breeding population of Black Brant. Text Branta bernicla Kuskokwim Alaska Yukon BioOne Online Journals Brant ENVELOPE(7.105,7.105,62.917,62.917) Yukon The Condor 113 3 511 517 |
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Open Polar |
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BioOne Online Journals |
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ftbioone |
language |
English |
description |
We estimated first-year and adult survival of Black Brant (Branta bernicla nigricans) from the Yukon—Kuskokwim Delta, Alaska, to assess (1) the role that first-year survival plays in declining recruitment and in the local breeding population's decline since the early 1980s and (2) the potential role of subsistence harvest in declining first-year survival. We used band-recovery models in program Mark to estimate band-recovery rates and annual survival from 1986 to 2007. The only models of band recoveries that received support contained annual variation and an additive effect of sex on band-recovery rates. The two best-supported models of annual survival differentiated between first-year and older Black Brant. The best-supported model (Akaike weight = 0.69) included a linear trend in first-year survival, while the second best-supported model (Akaike weight = 0.20) included an effect of mean gosling mass on first-year survival. Band-recovery rates corresponded to harvest rates of ∼1%, indicating that during the study period harvest was not demographically important. Adult survival was comparable (0.87) to that from other studies of this population, while first-year survival declined from 0.46 in 1986 to 0.24 in 2007. The trend of decline in first-year survival represented the effects of variation in conditions for goslings' growth in the breeding area combined with unknown effects on migration and in the wintering areas. Declining first-year survival is an important contributor to decline in the local breeding population of Black Brant. |
author2 |
James S. Sedinger Christopher A. Nicolai |
format |
Text |
author |
James S. Sedinger Christopher A. Nicolai |
spellingShingle |
James S. Sedinger Christopher A. Nicolai Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
author_facet |
James S. Sedinger Christopher A. Nicolai |
author_sort |
James S. Sedinger |
title |
Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
title_short |
Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
title_full |
Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
title_fullStr |
Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
title_full_unstemmed |
Recent Trends in First-Year Survival for Black Brant Breeding in Southwestern Alaska |
title_sort |
recent trends in first-year survival for black brant breeding in southwestern alaska |
publisher |
American Ornithological Society |
publishDate |
2011 |
url |
https://doi.org/10.1525/cond.2011.100218 |
op_coverage |
world |
long_lat |
ENVELOPE(7.105,7.105,62.917,62.917) |
geographic |
Brant Yukon |
geographic_facet |
Brant Yukon |
genre |
Branta bernicla Kuskokwim Alaska Yukon |
genre_facet |
Branta bernicla Kuskokwim Alaska Yukon |
op_source |
https://doi.org/10.1525/cond.2011.100218 |
op_relation |
doi:10.1525/cond.2011.100218 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.1525/cond.2011.100218 |
container_title |
The Condor |
container_volume |
113 |
container_issue |
3 |
container_start_page |
511 |
op_container_end_page |
517 |
_version_ |
1772813545562439680 |