Population decline in the Delta caribou herd with reference to other Alaskan herds
After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adu...
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1996
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Online Access: | https://septentrio.uit.no/index.php/rangifer/article/view/1221 https://doi.org/10.7557/2.16.4.1221 |
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ftunitroemsoe:oai:ojs.henry.ub.uit.no:article/1221 2023-05-15T15:50:30+02:00 Population decline in the Delta caribou herd with reference to other Alaskan herds Valkenburg , Patrick 1996-01-01 application/pdf https://septentrio.uit.no/index.php/rangifer/article/view/1221 https://doi.org/10.7557/2.16.4.1221 eng eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/rangifer/article/view/1221/1160 https://septentrio.uit.no/index.php/rangifer/article/view/1221 doi:10.7557/2.16.4.1221 Copyright (c) 2015 Patrick Valkenburg et al. http://creativecommons.org/licenses/by/3.0/ CC-BY Rangifer; Vol 16 (1996): Special Issue No. 9; 53-62 1890-6729 caribou rainfall Rangifer snow temperature weather wolves Delta herd population decline Alaska info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 1996 ftunitroemsoe https://doi.org/10.7557/2.16.4.1221 2021-08-16T14:53:01Z After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adult females. Other minor causes included increased winter mortality of calves, and reduced parturition rates of 3-year-old and older females. The decline in the Delta herd also coincided with increased wolf (Canis lupus) numbers, winters with deeper than normal snow, and warm summers. Mean body weight of annual samples of 10-month-old female calves was consistently low during the decline. Except in some of the smallest Interior Alaskan herds, we conclude that evidence for population regulation in Alaskan caribou is weak, and that herds are likely to fluctuate within a wide range of densities due to complex interactions of predation and weather. Unless wolf numbers are influenced by man, the size of a caribou herd in a given year is likely to be largely a function of its size during the previous population low and the number of years of favorable weather in the interim. Article in Journal/Newspaper Canis lupus Rangifer Alaska University of Tromsø: Septentrio Academic Publishing Rangifer 16 4 53 |
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Open Polar |
collection |
University of Tromsø: Septentrio Academic Publishing |
op_collection_id |
ftunitroemsoe |
language |
English |
topic |
caribou rainfall Rangifer snow temperature weather wolves Delta herd population decline Alaska |
spellingShingle |
caribou rainfall Rangifer snow temperature weather wolves Delta herd population decline Alaska Valkenburg , Patrick Population decline in the Delta caribou herd with reference to other Alaskan herds |
topic_facet |
caribou rainfall Rangifer snow temperature weather wolves Delta herd population decline Alaska |
description |
After growing continuously for nearly 15 years, the Delta caribou herd began to decline in 1989. Most other Interior Alaskan herds also began declining. In the Delta herd, and in other herds, the declines were caused primarily by high summer mortality of calves and increased natural mortality of adult females. Other minor causes included increased winter mortality of calves, and reduced parturition rates of 3-year-old and older females. The decline in the Delta herd also coincided with increased wolf (Canis lupus) numbers, winters with deeper than normal snow, and warm summers. Mean body weight of annual samples of 10-month-old female calves was consistently low during the decline. Except in some of the smallest Interior Alaskan herds, we conclude that evidence for population regulation in Alaskan caribou is weak, and that herds are likely to fluctuate within a wide range of densities due to complex interactions of predation and weather. Unless wolf numbers are influenced by man, the size of a caribou herd in a given year is likely to be largely a function of its size during the previous population low and the number of years of favorable weather in the interim. |
format |
Article in Journal/Newspaper |
author |
Valkenburg , Patrick |
author_facet |
Valkenburg , Patrick |
author_sort |
Valkenburg , Patrick |
title |
Population decline in the Delta caribou herd with reference to other Alaskan herds |
title_short |
Population decline in the Delta caribou herd with reference to other Alaskan herds |
title_full |
Population decline in the Delta caribou herd with reference to other Alaskan herds |
title_fullStr |
Population decline in the Delta caribou herd with reference to other Alaskan herds |
title_full_unstemmed |
Population decline in the Delta caribou herd with reference to other Alaskan herds |
title_sort |
population decline in the delta caribou herd with reference to other alaskan herds |
publisher |
Septentrio Academic Publishing |
publishDate |
1996 |
url |
https://septentrio.uit.no/index.php/rangifer/article/view/1221 https://doi.org/10.7557/2.16.4.1221 |
genre |
Canis lupus Rangifer Alaska |
genre_facet |
Canis lupus Rangifer Alaska |
op_source |
Rangifer; Vol 16 (1996): Special Issue No. 9; 53-62 1890-6729 |
op_relation |
https://septentrio.uit.no/index.php/rangifer/article/view/1221/1160 https://septentrio.uit.no/index.php/rangifer/article/view/1221 doi:10.7557/2.16.4.1221 |
op_rights |
Copyright (c) 2015 Patrick Valkenburg et al. http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.7557/2.16.4.1221 |
container_title |
Rangifer |
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16 |
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4 |
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53 |
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1766385462478372864 |