Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition
Abstract While foraging, a predator can feed solitarily or in a group. The net energy gain of joining a group is predicted to vary with prey patch quality, species-specific prey capture behavior, and the size and species composition of the predator group. In coastal Newfoundland, Canada, capelin (Ma...
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Online Access: | http://dx.doi.org/10.1093/auk/ukz062 http://academic.oup.com/auk/article-pdf/137/1/ukz062/31744838/ukz062.pdf |
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croxfordunivpr:10.1093/auk/ukz062 2023-10-01T03:56:02+02:00 Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition Maynard, Laurie D Carvalho, Paloma C Davoren, Gail K Natural Sciences and Engineering Research Council of Canada Natural Sciences and Engineering Research Council of Canada Ship Time Grants University of Manitoba Faculty of Science Fieldwork Support Program Manitoba Graduate Fellowship CAPES 2019 http://dx.doi.org/10.1093/auk/ukz062 http://academic.oup.com/auk/article-pdf/137/1/ukz062/31744838/ukz062.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model The Auk volume 137, issue 1 ISSN 0004-8038 1938-4254 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 2019 croxfordunivpr https://doi.org/10.1093/auk/ukz062 2023-09-08T10:43:25Z Abstract While foraging, a predator can feed solitarily or in a group. The net energy gain of joining a group is predicted to vary with prey patch quality, species-specific prey capture behavior, and the size and species composition of the predator group. In coastal Newfoundland, Canada, capelin (Mallotus villosus), a key forage fish, migrates inshore to spawn during the summer, resulting in a dramatic shift in prey availability. During July–August 2015–2017, we examined the numerical and behavioral responses of procellarid (Great Shearwater [Ardenna gravis], Sooty Shearwater [A. grisea], Northern Fulmar [Fulmarus glacialis]), and gull species (Herring Gull [Larus argentatus], Great Black-backed Gull [L. marinus]) to fish offal under varying capelin availability as well as flock size and composition using an at-sea experiment on the northeast Newfoundland coast. The experiment consisted of providing offal every 30 s (10-min experimental period), along with 10-min control periods before and after. We recorded the species-specific number of birds on the water, the number of birds simultaneously attempting to capture offal, and the number of successful attempts (“foraging success”). The number of birds on the water was lower during high capelin availability for all species, except for Northern Fulmar. The number of conspecifics simultaneously attempting to capture offal increased with the number of conspecifics on the water, but plateaued at different numbers (4–17) for most species. The species-specific proportion of successful attempts (i.e. foraging success) varied with flock size and composition (i.e. number of conspecifics, heterospecifics, species). Foraging success of Herring Gulls and fulmars were moderately affected by flock size and composition, suggesting that they may be dominant competitors. Findings suggest that seabirds rely more heavily on supplemental food sources, such as fisheries discards and offal, when natural prey availability declines, potentially resulting in a higher risk of by-catch ... Article in Journal/Newspaper Fulmarus glacialis Newfoundland Northern Fulmar Oxford University Press (via Crossref) Canada Fulmar ENVELOPE(-46.016,-46.016,-60.616,-60.616) The Auk 137 1 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
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 Maynard, Laurie D Carvalho, Paloma C Davoren, Gail K Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Abstract While foraging, a predator can feed solitarily or in a group. The net energy gain of joining a group is predicted to vary with prey patch quality, species-specific prey capture behavior, and the size and species composition of the predator group. In coastal Newfoundland, Canada, capelin (Mallotus villosus), a key forage fish, migrates inshore to spawn during the summer, resulting in a dramatic shift in prey availability. During July–August 2015–2017, we examined the numerical and behavioral responses of procellarid (Great Shearwater [Ardenna gravis], Sooty Shearwater [A. grisea], Northern Fulmar [Fulmarus glacialis]), and gull species (Herring Gull [Larus argentatus], Great Black-backed Gull [L. marinus]) to fish offal under varying capelin availability as well as flock size and composition using an at-sea experiment on the northeast Newfoundland coast. The experiment consisted of providing offal every 30 s (10-min experimental period), along with 10-min control periods before and after. We recorded the species-specific number of birds on the water, the number of birds simultaneously attempting to capture offal, and the number of successful attempts (“foraging success”). The number of birds on the water was lower during high capelin availability for all species, except for Northern Fulmar. The number of conspecifics simultaneously attempting to capture offal increased with the number of conspecifics on the water, but plateaued at different numbers (4–17) for most species. The species-specific proportion of successful attempts (i.e. foraging success) varied with flock size and composition (i.e. number of conspecifics, heterospecifics, species). Foraging success of Herring Gulls and fulmars were moderately affected by flock size and composition, suggesting that they may be dominant competitors. Findings suggest that seabirds rely more heavily on supplemental food sources, such as fisheries discards and offal, when natural prey availability declines, potentially resulting in a higher risk of by-catch ... |
author2 |
Natural Sciences and Engineering Research Council of Canada Natural Sciences and Engineering Research Council of Canada Ship Time Grants University of Manitoba Faculty of Science Fieldwork Support Program Manitoba Graduate Fellowship CAPES |
format |
Article in Journal/Newspaper |
author |
Maynard, Laurie D Carvalho, Paloma C Davoren, Gail K |
author_facet |
Maynard, Laurie D Carvalho, Paloma C Davoren, Gail K |
author_sort |
Maynard, Laurie D |
title |
Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
title_short |
Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
title_full |
Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
title_fullStr |
Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
title_full_unstemmed |
Seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
title_sort |
seabirds vary responses to supplemental food under dynamic natural prey availability and feeding aggregation composition |
publisher |
Oxford University Press (OUP) |
publishDate |
2019 |
url |
http://dx.doi.org/10.1093/auk/ukz062 http://academic.oup.com/auk/article-pdf/137/1/ukz062/31744838/ukz062.pdf |
long_lat |
ENVELOPE(-46.016,-46.016,-60.616,-60.616) |
geographic |
Canada Fulmar |
geographic_facet |
Canada Fulmar |
genre |
Fulmarus glacialis Newfoundland Northern Fulmar |
genre_facet |
Fulmarus glacialis Newfoundland Northern Fulmar |
op_source |
The Auk volume 137, issue 1 ISSN 0004-8038 1938-4254 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/auk/ukz062 |
container_title |
The Auk |
container_volume |
137 |
container_issue |
1 |
_version_ |
1778525127379517440 |