PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY
Summary Feeding methods and relations of Great Skuas and Arctic Skuas to prey were studied in a seabird colony at Hermaness, Shetland. Great Skuas obtained food by kleptoparasitism, predation and scavenging. They induced Gannets to regurgitate by interfering with their flight; grasping the Gannet by...
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Online Access: | http://dx.doi.org/10.1111/j.1474-919x.1976.tb03066.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1976.tb03066.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1976.tb03066.x |
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crwiley:10.1111/j.1474-919x.1976.tb03066.x 2024-06-23T07:50:19+00:00 PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY Andersson, Malte 1976 http://dx.doi.org/10.1111/j.1474-919x.1976.tb03066.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1976.tb03066.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1976.tb03066.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ibis volume 118, issue 2, page 208-217 ISSN 0019-1019 1474-919X journal-article 1976 crwiley https://doi.org/10.1111/j.1474-919x.1976.tb03066.x 2024-05-31T08:13:40Z Summary Feeding methods and relations of Great Skuas and Arctic Skuas to prey were studied in a seabird colony at Hermaness, Shetland. Great Skuas obtained food by kleptoparasitism, predation and scavenging. They induced Gannets to regurgitate by interfering with their flight; grasping the Gannet by the wing or tail or pushing it down with the feet on its back. Gannets tried to escape by descending to the surface, and regurgitated during 12% of the chases, most frequently when pursued by several birds. Great Skuas caught Puffins by swooping at flocks in the colony. Puffins flying with fish to their young were also chased, releasing food on one fifth of the attacks, or escaping down to the sea and diving. Great Skuas also took Kittiwake nestlings by hovering and grasping the chick with the bill, killing and eating it on the surface. Adult Kittiwakes from nearby nests took to the air, mobbing the predator. More Kittiwakes were engaged in mobbing at unsuccessful than at successful predation attempts, indicating that colonial breeding may be of selective value under such predation. Two different estimates pointed to a Kittiwake nestling predation of 0–12 and 014 young per pair. Fledging success of Kittiwakes was estimated at 0–87‐1‐06 young per pair, considerably lower than at English colonies where predators are absent. In spite of the predation, the Kittiwake colony showed no signs of decrease. Agonistic behaviour and other evidence indicate that Great Skuas defend feeding territories at the seabird colony. Skuas, gulls and Fulmars competed for food at carcasses. Fulmars dominated and chased away skuas. Arctic Skuas deprived Puffins of food. They patrolled the cliff, intercepting Puffins arriving with fish, snatching it from their victim's bill, or inducing them to release fish. Puffins continuing their inward flight lost food more often (30%) than birds descending to the sea (15%)—sometimes diving below. This opportunity to escape may explain the lower success of skuas at Hermaness than at a Puffin colony farther ... Article in Journal/Newspaper Arctic Wiley Online Library Arctic Ibis 118 2 208 217 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
Summary Feeding methods and relations of Great Skuas and Arctic Skuas to prey were studied in a seabird colony at Hermaness, Shetland. Great Skuas obtained food by kleptoparasitism, predation and scavenging. They induced Gannets to regurgitate by interfering with their flight; grasping the Gannet by the wing or tail or pushing it down with the feet on its back. Gannets tried to escape by descending to the surface, and regurgitated during 12% of the chases, most frequently when pursued by several birds. Great Skuas caught Puffins by swooping at flocks in the colony. Puffins flying with fish to their young were also chased, releasing food on one fifth of the attacks, or escaping down to the sea and diving. Great Skuas also took Kittiwake nestlings by hovering and grasping the chick with the bill, killing and eating it on the surface. Adult Kittiwakes from nearby nests took to the air, mobbing the predator. More Kittiwakes were engaged in mobbing at unsuccessful than at successful predation attempts, indicating that colonial breeding may be of selective value under such predation. Two different estimates pointed to a Kittiwake nestling predation of 0–12 and 014 young per pair. Fledging success of Kittiwakes was estimated at 0–87‐1‐06 young per pair, considerably lower than at English colonies where predators are absent. In spite of the predation, the Kittiwake colony showed no signs of decrease. Agonistic behaviour and other evidence indicate that Great Skuas defend feeding territories at the seabird colony. Skuas, gulls and Fulmars competed for food at carcasses. Fulmars dominated and chased away skuas. Arctic Skuas deprived Puffins of food. They patrolled the cliff, intercepting Puffins arriving with fish, snatching it from their victim's bill, or inducing them to release fish. Puffins continuing their inward flight lost food more often (30%) than birds descending to the sea (15%)—sometimes diving below. This opportunity to escape may explain the lower success of skuas at Hermaness than at a Puffin colony farther ... |
format |
Article in Journal/Newspaper |
author |
Andersson, Malte |
spellingShingle |
Andersson, Malte PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
author_facet |
Andersson, Malte |
author_sort |
Andersson, Malte |
title |
PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
title_short |
PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
title_full |
PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
title_fullStr |
PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
title_full_unstemmed |
PREDATION AND KLEPTOPARASITISM BY SKUAS IN A SHETLAND SEABIRD COLONY |
title_sort |
predation and kleptoparasitism by skuas in a shetland seabird colony |
publisher |
Wiley |
publishDate |
1976 |
url |
http://dx.doi.org/10.1111/j.1474-919x.1976.tb03066.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1474-919X.1976.tb03066.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1474-919X.1976.tb03066.x |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Ibis volume 118, issue 2, page 208-217 ISSN 0019-1019 1474-919X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1474-919x.1976.tb03066.x |
container_title |
Ibis |
container_volume |
118 |
container_issue |
2 |
container_start_page |
208 |
op_container_end_page |
217 |
_version_ |
1802641190459277312 |