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...
Published in: | Rangifer |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Septentrio Academic Publishing
1996
|
Subjects: | |
Online Access: | https://doi.org/10.7557/2.16.4.1221 https://doaj.org/article/3599bf5695244619af002463e8e7d6a7 |
id |
ftdoajarticles:oai:doaj.org/article:3599bf5695244619af002463e8e7d6a7 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:3599bf5695244619af002463e8e7d6a7 2023-05-15T15:50:33+02:00 Population decline in the Delta caribou herd with reference to other Alaskan herds Patrick Valkenburg 1996-01-01T00:00:00Z https://doi.org/10.7557/2.16.4.1221 https://doaj.org/article/3599bf5695244619af002463e8e7d6a7 EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/rangifer/article/view/1221 https://doaj.org/toc/1890-6729 doi:10.7557/2.16.4.1221 1890-6729 https://doaj.org/article/3599bf5695244619af002463e8e7d6a7 Rangifer, Vol 16, Iss 4 (1996) caribou rainfall Rangifer snow temperature weather Animal culture SF1-1100 article 1996 ftdoajarticles https://doi.org/10.7557/2.16.4.1221 2022-12-31T00:29:39Z 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 caribou Rangifer Directory of Open Access Journals: DOAJ Articles Rangifer 16 4 53 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
caribou rainfall Rangifer snow temperature weather Animal culture SF1-1100 |
spellingShingle |
caribou rainfall Rangifer snow temperature weather Animal culture SF1-1100 Patrick Valkenburg Population decline in the Delta caribou herd with reference to other Alaskan herds |
topic_facet |
caribou rainfall Rangifer snow temperature weather Animal culture SF1-1100 |
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 |
Patrick Valkenburg |
author_facet |
Patrick Valkenburg |
author_sort |
Patrick Valkenburg |
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://doi.org/10.7557/2.16.4.1221 https://doaj.org/article/3599bf5695244619af002463e8e7d6a7 |
genre |
Canis lupus caribou Rangifer |
genre_facet |
Canis lupus caribou Rangifer |
op_source |
Rangifer, Vol 16, Iss 4 (1996) |
op_relation |
https://septentrio.uit.no/index.php/rangifer/article/view/1221 https://doaj.org/toc/1890-6729 doi:10.7557/2.16.4.1221 1890-6729 https://doaj.org/article/3599bf5695244619af002463e8e7d6a7 |
op_doi |
https://doi.org/10.7557/2.16.4.1221 |
container_title |
Rangifer |
container_volume |
16 |
container_issue |
4 |
container_start_page |
53 |
_version_ |
1766385532581969920 |