Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska
Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence fut...
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2011
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ftbioone:10.1002/jwmg.24 2024-06-02T08:04:32+00:00 Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber world 2011-01-01 text/HTML https://doi.org/10.1002/jwmg.24 en eng The Wildlife Society doi:10.1002/jwmg.24 All rights reserved. https://doi.org/10.1002/jwmg.24 Text 2011 ftbioone https://doi.org/10.1002/jwmg.24 2024-05-07T00:47:03Z Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence future survival and productivity. In 2006–2008, we studied gosling growth at 3 of the 4 major colonies on the YukonKuskokwim Delta, Alaska. Estimates of age-adjusted gosling mass at the 2 southern colonies (approx. 30% of the world population of breeding black brack) was low (gosling mass at 30.5 days ranged 346.7 ± 42.5 g to 627.1 ± 15.9 g) in comparison to a third colony (gosling mass at 30.5 days ranged 640.0 ± 8.3 g to 821.6 ± 13.6 g) and to most previous estimates of age-adjusted mass of brant goslings. Thus, our results are consistent with the hypothesis that poor gosling growth is negatively influencing the brant population. There are 2 non-mutually exclusive explanations for the apparent growth rates we observed. First, the population decline may have been caused by density-independent factors and habitat capacity has declined along with the population as a consequence of the unique foraging feedback between brant and their grazing habitats. Alternatively, a reduction in habitat capacity, as a result of changes to the grazing system, may have negatively influenced gosling growth, which is contributing to the overall long-term population decline. We found support for both explanations. For colonies over habitat capacity we recommend management to enhance foraging habitat, whereas for colonies below habitat capacity we recommend management to increase nesting productivity. Text Branta bernicla Kuskokwim Alaska Yukon BioOne Online Journals Brant ENVELOPE(7.105,7.105,62.917,62.917) Yukon The Journal of Wildlife Management 75 1 101 108 |
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English |
description |
Recent declines in black brant (Branta bernicla nigricans) are likely the result of low recruitment. In geese, recruitment is strongly affected by habitat conditions experienced by broods because gosling growth rates are indicative of forage conditions during brood rearing and strongly influence future survival and productivity. In 2006–2008, we studied gosling growth at 3 of the 4 major colonies on the YukonKuskokwim Delta, Alaska. Estimates of age-adjusted gosling mass at the 2 southern colonies (approx. 30% of the world population of breeding black brack) was low (gosling mass at 30.5 days ranged 346.7 ± 42.5 g to 627.1 ± 15.9 g) in comparison to a third colony (gosling mass at 30.5 days ranged 640.0 ± 8.3 g to 821.6 ± 13.6 g) and to most previous estimates of age-adjusted mass of brant goslings. Thus, our results are consistent with the hypothesis that poor gosling growth is negatively influencing the brant population. There are 2 non-mutually exclusive explanations for the apparent growth rates we observed. First, the population decline may have been caused by density-independent factors and habitat capacity has declined along with the population as a consequence of the unique foraging feedback between brant and their grazing habitats. Alternatively, a reduction in habitat capacity, as a result of changes to the grazing system, may have negatively influenced gosling growth, which is contributing to the overall long-term population decline. We found support for both explanations. For colonies over habitat capacity we recommend management to enhance foraging habitat, whereas for colonies below habitat capacity we recommend management to increase nesting productivity. |
author2 |
Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber |
format |
Text |
author |
Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber |
spellingShingle |
Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
author_facet |
Thomas F. Fondell Paul L. Flint James S. Sedinger Christopher A. Nicolai Jason L. Schamber |
author_sort |
Thomas F. Fondell |
title |
Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
title_short |
Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
title_full |
Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
title_fullStr |
Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
title_full_unstemmed |
Intercolony Variation in Growth of Black Brant Goslings on the Yukon-Kuskokwim Delta, Alaska |
title_sort |
intercolony variation in growth of black brant goslings on the yukon-kuskokwim delta, alaska |
publisher |
The Wildlife Society |
publishDate |
2011 |
url |
https://doi.org/10.1002/jwmg.24 |
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/10.1002/jwmg.24 |
op_relation |
doi:10.1002/jwmg.24 |
op_rights |
All rights reserved. |
op_doi |
https://doi.org/10.1002/jwmg.24 |
container_title |
The Journal of Wildlife Management |
container_volume |
75 |
container_issue |
1 |
container_start_page |
101 |
op_container_end_page |
108 |
_version_ |
1800749172837580800 |