Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska
Abstract We conducted an experiment to study the effect of gosling density on food abundance and feeding behavior of Black Brant (Branta bernicla) goslings in two habitat types important to Black Brant on the Yukon-Kuskokwim Delta, Alaska: (1) Carex subspathacea grazing lawns and (2) slough levees t...
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Oxford University Press (OUP)
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Online Access: | http://dx.doi.org/10.1093/auk/121.1.210 http://academic.oup.com/auk/article-pdf/121/1/210/29688265/auk0210.pdf |
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croxfordunivpr:10.1093/auk/121.1.210 2024-04-07T07:51:33+00:00 Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska Herzog, Mark P. Sedinger, James S. Grubb Jr., T. C. 2004 http://dx.doi.org/10.1093/auk/121.1.210 http://academic.oup.com/auk/article-pdf/121/1/210/29688265/auk0210.pdf en eng Oxford University Press (OUP) The Auk volume 121, issue 1, page 210-223 ISSN 1938-4254 0004-8038 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 2004 croxfordunivpr https://doi.org/10.1093/auk/121.1.210 2024-03-08T03:01:35Z Abstract We conducted an experiment to study the effect of gosling density on food abundance and feeding behavior of Black Brant (Branta bernicla) goslings in two habitat types important to Black Brant on the Yukon-Kuskokwim Delta, Alaska: (1) Carex subspathacea grazing lawns and (2) slough levees that contain Triglochin palustris. Within each habitat, we manipulated grazing pressure by allowing goslings to graze specific plots every 6, 9, or 12 days. We randomly assigned six goslings to one of six treatment groups (three grazing frequencies × two habitats). Biomass of C. subspathacea was higher in lightly grazed plots (grazed every 12 days) than in the heavily grazed plots (grazed every 6 days). Offtake in C. subspathacea was also greater in the lightly grazed plots. Within C. subspathacea stands, proportion of time spent feeding varied among grazing intensities. Goslings within heavily grazed plots spent more time feeding than goslings in lightly grazed plots. Within slough levee habitat, there were no differences between heavily and lightly grazed plots in either biomass or offtake of T. palustris. Whereas overall percentage of time feeding did not vary between the two habitats, percentage of time feeding declined as gosling mass increased in all treatments and habitats. Although the trend in peck rate over time varied among treatments and between habitats, during trials very early in the season we observed a reduced peck rate in the heavily grazed treatment, but only within the C. subspathacea grazing lawns. There was no variation in peck rate among treatments within slough levee habitat; however, peck rates for goslings fed on C. subspathacea was double the rate of goslings in slough levee. Thus, the varied growth responses of plants between habitats to variation in grazing pressure that we observed during this experiment suggest the importance of density-dependent effects on brood-rearing habitat and the resulting variation in gosling growth. Article in Journal/Newspaper Branta bernicla Kuskokwim Alaska Yukon Oxford University Press Yukon Brant ENVELOPE(7.105,7.105,62.917,62.917) The Auk 121 1 210 223 |
institution |
Open Polar |
collection |
Oxford University Press |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Herzog, Mark P. Sedinger, James S. Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Abstract We conducted an experiment to study the effect of gosling density on food abundance and feeding behavior of Black Brant (Branta bernicla) goslings in two habitat types important to Black Brant on the Yukon-Kuskokwim Delta, Alaska: (1) Carex subspathacea grazing lawns and (2) slough levees that contain Triglochin palustris. Within each habitat, we manipulated grazing pressure by allowing goslings to graze specific plots every 6, 9, or 12 days. We randomly assigned six goslings to one of six treatment groups (three grazing frequencies × two habitats). Biomass of C. subspathacea was higher in lightly grazed plots (grazed every 12 days) than in the heavily grazed plots (grazed every 6 days). Offtake in C. subspathacea was also greater in the lightly grazed plots. Within C. subspathacea stands, proportion of time spent feeding varied among grazing intensities. Goslings within heavily grazed plots spent more time feeding than goslings in lightly grazed plots. Within slough levee habitat, there were no differences between heavily and lightly grazed plots in either biomass or offtake of T. palustris. Whereas overall percentage of time feeding did not vary between the two habitats, percentage of time feeding declined as gosling mass increased in all treatments and habitats. Although the trend in peck rate over time varied among treatments and between habitats, during trials very early in the season we observed a reduced peck rate in the heavily grazed treatment, but only within the C. subspathacea grazing lawns. There was no variation in peck rate among treatments within slough levee habitat; however, peck rates for goslings fed on C. subspathacea was double the rate of goslings in slough levee. Thus, the varied growth responses of plants between habitats to variation in grazing pressure that we observed during this experiment suggest the importance of density-dependent effects on brood-rearing habitat and the resulting variation in gosling growth. |
author2 |
Grubb Jr., T. C. |
format |
Article in Journal/Newspaper |
author |
Herzog, Mark P. Sedinger, James S. |
author_facet |
Herzog, Mark P. Sedinger, James S. |
author_sort |
Herzog, Mark P. |
title |
Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
title_short |
Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
title_full |
Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
title_fullStr |
Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
title_full_unstemmed |
Dynamics of Foraging Behavior Associated With Variation in Habitat and Forage Availability in Captive Black Brant (Branta Bernicla Nigricans) Goslings in Alaska |
title_sort |
dynamics of foraging behavior associated with variation in habitat and forage availability in captive black brant (branta bernicla nigricans) goslings in alaska |
publisher |
Oxford University Press (OUP) |
publishDate |
2004 |
url |
http://dx.doi.org/10.1093/auk/121.1.210 http://academic.oup.com/auk/article-pdf/121/1/210/29688265/auk0210.pdf |
long_lat |
ENVELOPE(7.105,7.105,62.917,62.917) |
geographic |
Yukon Brant |
geographic_facet |
Yukon Brant |
genre |
Branta bernicla Kuskokwim Alaska Yukon |
genre_facet |
Branta bernicla Kuskokwim Alaska Yukon |
op_source |
The Auk volume 121, issue 1, page 210-223 ISSN 1938-4254 0004-8038 |
op_doi |
https://doi.org/10.1093/auk/121.1.210 |
container_title |
The Auk |
container_volume |
121 |
container_issue |
1 |
container_start_page |
210 |
op_container_end_page |
223 |
_version_ |
1795666550936567808 |