Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay
Numbers of Kelp Gulls recorded within the Port Elizabeth area peaked in the austral autumn, and on average comprised approximately 4% of the southern African population. Between 66% and 80% of Kelp Gulls recorded around Port Elizabeth were in adult plumage. It is assumed that adults breeding outside...
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Ostrich: Journal of African Ornithology
2006
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ftjafricanj:oai:ojs.ajol.info:article/20233 2023-05-15T15:44:40+02:00 Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay PA Whittington NTW Klages AP Martin 2006-11-24 application/pdf http://ajol.info/index.php/ostrich/article/view/20233 en eng Ostrich: Journal of African Ornithology http://ajol.info/index.php/ostrich/article/view/20233 Copyright for articles published in this journal is retained by the journal. Ostrich: Journal of African Ornithology; Vol 77 (2006); 195-201 Peer-reviewed Article 2006 ftjafricanj 2010-01-05T09:26:37Z Numbers of Kelp Gulls recorded within the Port Elizabeth area peaked in the austral autumn, and on average comprised approximately 4% of the southern African population. Between 66% and 80% of Kelp Gulls recorded around Port Elizabeth were in adult plumage. It is assumed that adults breeding outside of the Port Elizabeth area move into the area after breeding. During their first year Kelp Gulls showed distinct periods of influx — thought to be due to the fledging of local birds — followed by a movement of birds into the region from further west. Birds are thought to be attracted to the urban environment by sources of human-provided foodstuffs available at the harbour and at a municipal rubbish tip. Seasonal patterns differed across sites in the Port Elizabeth area and were rarely the same for all age categories at any one site. Numbers of birds at roosts did not appear to be correlated to the state of the tide, but numbers foraging on the Swartkops estuary were. Numbers of adult Kelp Gulls at Bird Island peaked during the breeding season. Juvenile birds left the island soon after fledging. Ostrich 2006, 77(3&4): 195–201 Article in Journal/Newspaper Bird Island AJOL - African Journals Online Austral Bird Island ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
institution |
Open Polar |
collection |
AJOL - African Journals Online |
op_collection_id |
ftjafricanj |
language |
English |
description |
Numbers of Kelp Gulls recorded within the Port Elizabeth area peaked in the austral autumn, and on average comprised approximately 4% of the southern African population. Between 66% and 80% of Kelp Gulls recorded around Port Elizabeth were in adult plumage. It is assumed that adults breeding outside of the Port Elizabeth area move into the area after breeding. During their first year Kelp Gulls showed distinct periods of influx — thought to be due to the fledging of local birds — followed by a movement of birds into the region from further west. Birds are thought to be attracted to the urban environment by sources of human-provided foodstuffs available at the harbour and at a municipal rubbish tip. Seasonal patterns differed across sites in the Port Elizabeth area and were rarely the same for all age categories at any one site. Numbers of birds at roosts did not appear to be correlated to the state of the tide, but numbers foraging on the Swartkops estuary were. Numbers of adult Kelp Gulls at Bird Island peaked during the breeding season. Juvenile birds left the island soon after fledging. Ostrich 2006, 77(3&4): 195–201 |
format |
Article in Journal/Newspaper |
author |
PA Whittington NTW Klages AP Martin |
spellingShingle |
PA Whittington NTW Klages AP Martin Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
author_facet |
PA Whittington NTW Klages AP Martin |
author_sort |
PA Whittington |
title |
Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
title_short |
Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
title_full |
Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
title_fullStr |
Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
title_full_unstemmed |
Seasonal patterns in numbers of Kelp Gulls Larus dominicanus vetula in the Port Elizabeth area and on Bird Island, Algoa Bay |
title_sort |
seasonal patterns in numbers of kelp gulls larus dominicanus vetula in the port elizabeth area and on bird island, algoa bay |
publisher |
Ostrich: Journal of African Ornithology |
publishDate |
2006 |
url |
http://ajol.info/index.php/ostrich/article/view/20233 |
long_lat |
ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
geographic |
Austral Bird Island |
geographic_facet |
Austral Bird Island |
genre |
Bird Island |
genre_facet |
Bird Island |
op_source |
Ostrich: Journal of African Ornithology; Vol 77 (2006); 195-201 |
op_relation |
http://ajol.info/index.php/ostrich/article/view/20233 |
op_rights |
Copyright for articles published in this journal is retained by the journal. |
_version_ |
1766379046408552448 |