Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories
Information regarding the status of common eiders, Somateria mollissima, breeding in the Canadian Arctic is sorely lacking. In 1997, we surveyed five island archipelagoes in the Belcher Islands in Hudson Bay (56 00 - 57 30 N, 79 30 - 80 00 W) from 3 to 23 July. Our results were compared with eider s...
Published in: | ARCTIC |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
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The Arctic Institute of North America
1998
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Online Access: | https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137 |
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Open Polar |
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University of Calgary Journal Hosting |
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ftunivcalgaryojs |
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English |
topic |
common eider Somateria mollissima sedentaria Belcher Islands population decline Hudson Bay eider à duvet îles Belcher déclin de population baie d’Hudson |
spellingShingle |
common eider Somateria mollissima sedentaria Belcher Islands population decline Hudson Bay eider à duvet îles Belcher déclin de population baie d’Hudson Robertson, Gregory J. Gilchrist, H. Grant Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
topic_facet |
common eider Somateria mollissima sedentaria Belcher Islands population decline Hudson Bay eider à duvet îles Belcher déclin de population baie d’Hudson |
description |
Information regarding the status of common eiders, Somateria mollissima, breeding in the Canadian Arctic is sorely lacking. In 1997, we surveyed five island archipelagoes in the Belcher Islands in Hudson Bay (56 00 - 57 30 N, 79 30 - 80 00 W) from 3 to 23 July. Our results were compared with eider surveys of the same islands completed between 1985 and 1989 using a standard protocol. We found 1416 eiders on 431 islands. Most (94.1%) were found while the female was still incubating. In all five island groups surveyed, the number of nesting eiders declined significantly (overall decline of 75.0% from 1985-88 to 1997, range: 62.3-84.0%). In 1997, nesting islands and adjacent waters were free of ice, and eiders nested early and laid large clutches (range: 4.0-4.4±1.0-1.2 SD). These conditions indicate a good nesting season, and we inferred that extensive nonbreeding by female eiders in 1997 did not account for the observed decline. A large reported die-off of eiders during the winter of 1991-92, which occurred when areas of open water froze, was the most likely cause of the decline. Our results raise serious conservation concerns, because eider populations are sensitive to reductions in adult survival and this population is harvested throughout the year by subsistence hunters. On a grandement besoin d'information sur le statut de l'eider à duvet Somateria mollissima qui niche dans l'Arctique canadien. En 1997, du 3 au 23 juillet, on a effectué des relevés dans cinq archipels des îles Belcher situées dans la baie d'Hudson (56°00'-57°30' N., 79°30'-80°00' O.) On a comparé nos résultats suivant un protocole normalisé à des relevés d'eiders effectués dans les mêmes îles entre 1985 et 1989. On a trouvé 1416 eiders dans 431 îles. La plupart (94,1 p. cent) ont été relevés alors que la femelle était encore en train de couver. Dans chacun des cinq groupes d'îles étudiés, le nombre d'eiders nicheurs avait enregistré une baisse importante (déclin global de 75,0 p. cent de 1985 à 1989, fourchette de 62,3 à 84,0 p. cent). En 1997, les îles de nidification et les eaux adjacentes étaient libres de glace; les eiders ont niché tôt et la taille des pontes était importante (fourchette: 4,0 à 4,4 ± écart-type de 1,0 à 1,2). Ces conditions sont révélatrices d'une bonne saison de reproduction, et nous en déduisons que la non-reproduction généralisée par les eiders femelles en 1997 n'explique pas le déclin enregistré. C'est très probablement la mortalité massive d'eiders enregistrée au cours de l'hiver de 1991-92, survenue quand les surfaces d'eau libre ont gelé, qui a été responsable du déclin. Nos résultats soulèvent d'importantes questions en matière de conservation, car les populations d'eiders sont sensibles aux baisses de survie adulte et que, tout au long de l'année, cette population fait l'objet de prélèvements dans le cadre de la chasse de subsistance. |
format |
Article in Journal/Newspaper |
author |
Robertson, Gregory J. Gilchrist, H. Grant |
author_facet |
Robertson, Gregory J. Gilchrist, H. Grant |
author_sort |
Robertson, Gregory J. |
title |
Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
title_short |
Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
title_full |
Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
title_fullStr |
Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
title_full_unstemmed |
Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories |
title_sort |
evidence of population declines among common eiders breeding in the belcher islands, northwest territories |
publisher |
The Arctic Institute of North America |
publishDate |
1998 |
url |
https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137 |
long_lat |
ENVELOPE(-78.666,-78.666,58.417,58.417) ENVELOPE(-74.999,-74.999,58.500,58.500) ENVELOPE(-94.172,-94.172,57.936,57.936) ENVELOPE(-79.250,-79.250,56.184,56.184) |
geographic |
Arctic Baie d'Hudson Baie-d'Hudson Belcher Belcher Islands Hudson Hudson Bay Northwest Territories |
geographic_facet |
Arctic Baie d'Hudson Baie-d'Hudson Belcher Belcher Islands Hudson Hudson Bay Northwest Territories |
genre |
Arctic Arctic Baie d'Hudson Belcher Islands Common Eider Eider à duvet Hudson Bay Northwest Territories Somateria mollissima |
genre_facet |
Arctic Arctic Baie d'Hudson Belcher Islands Common Eider Eider à duvet Hudson Bay Northwest Territories Somateria mollissima |
op_source |
ARCTIC; Vol. 51 No. 4 (1998): December: 301–416; 378-385 1923-1245 0004-0843 |
op_relation |
https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137/48072 https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137 |
container_title |
ARCTIC |
container_volume |
51 |
container_issue |
4 |
_version_ |
1766290735407038464 |
spelling |
ftunivcalgaryojs:oai:journalhosting.ucalgary.ca:article/64137 2023-05-15T14:19:09+02:00 Evidence of Population Declines among Common Eiders Breeding in the Belcher Islands, Northwest Territories Robertson, Gregory J. Gilchrist, H. Grant 1998-01-01 application/pdf https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137 eng eng The Arctic Institute of North America https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137/48072 https://journalhosting.ucalgary.ca/index.php/arctic/article/view/64137 ARCTIC; Vol. 51 No. 4 (1998): December: 301–416; 378-385 1923-1245 0004-0843 common eider Somateria mollissima sedentaria Belcher Islands population decline Hudson Bay eider à duvet îles Belcher déclin de population baie d’Hudson info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion research-article 1998 ftunivcalgaryojs 2022-03-22T21:21:19Z Information regarding the status of common eiders, Somateria mollissima, breeding in the Canadian Arctic is sorely lacking. In 1997, we surveyed five island archipelagoes in the Belcher Islands in Hudson Bay (56 00 - 57 30 N, 79 30 - 80 00 W) from 3 to 23 July. Our results were compared with eider surveys of the same islands completed between 1985 and 1989 using a standard protocol. We found 1416 eiders on 431 islands. Most (94.1%) were found while the female was still incubating. In all five island groups surveyed, the number of nesting eiders declined significantly (overall decline of 75.0% from 1985-88 to 1997, range: 62.3-84.0%). In 1997, nesting islands and adjacent waters were free of ice, and eiders nested early and laid large clutches (range: 4.0-4.4±1.0-1.2 SD). These conditions indicate a good nesting season, and we inferred that extensive nonbreeding by female eiders in 1997 did not account for the observed decline. A large reported die-off of eiders during the winter of 1991-92, which occurred when areas of open water froze, was the most likely cause of the decline. Our results raise serious conservation concerns, because eider populations are sensitive to reductions in adult survival and this population is harvested throughout the year by subsistence hunters. On a grandement besoin d'information sur le statut de l'eider à duvet Somateria mollissima qui niche dans l'Arctique canadien. En 1997, du 3 au 23 juillet, on a effectué des relevés dans cinq archipels des îles Belcher situées dans la baie d'Hudson (56°00'-57°30' N., 79°30'-80°00' O.) On a comparé nos résultats suivant un protocole normalisé à des relevés d'eiders effectués dans les mêmes îles entre 1985 et 1989. On a trouvé 1416 eiders dans 431 îles. La plupart (94,1 p. cent) ont été relevés alors que la femelle était encore en train de couver. Dans chacun des cinq groupes d'îles étudiés, le nombre d'eiders nicheurs avait enregistré une baisse importante (déclin global de 75,0 p. cent de 1985 à 1989, fourchette de 62,3 à 84,0 p. cent). En 1997, les îles de nidification et les eaux adjacentes étaient libres de glace; les eiders ont niché tôt et la taille des pontes était importante (fourchette: 4,0 à 4,4 ± écart-type de 1,0 à 1,2). Ces conditions sont révélatrices d'une bonne saison de reproduction, et nous en déduisons que la non-reproduction généralisée par les eiders femelles en 1997 n'explique pas le déclin enregistré. C'est très probablement la mortalité massive d'eiders enregistrée au cours de l'hiver de 1991-92, survenue quand les surfaces d'eau libre ont gelé, qui a été responsable du déclin. Nos résultats soulèvent d'importantes questions en matière de conservation, car les populations d'eiders sont sensibles aux baisses de survie adulte et que, tout au long de l'année, cette population fait l'objet de prélèvements dans le cadre de la chasse de subsistance. Article in Journal/Newspaper Arctic Arctic Baie d'Hudson Belcher Islands Common Eider Eider à duvet Hudson Bay Northwest Territories Somateria mollissima University of Calgary Journal Hosting Arctic Baie d'Hudson ENVELOPE(-78.666,-78.666,58.417,58.417) Baie-d'Hudson ENVELOPE(-74.999,-74.999,58.500,58.500) Belcher ENVELOPE(-94.172,-94.172,57.936,57.936) Belcher Islands ENVELOPE(-79.250,-79.250,56.184,56.184) Hudson Hudson Bay Northwest Territories ARCTIC 51 4 |