Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment
The Porcupine caribou (Rangifer tarandus granti) herd increased from approximately 100 000 animals during the 1970s to 178 000 in 1989, then declined to 129 000 by 1998. Our objective was to model the dynamics of this herd and investigate the potential that lower calf recruitment, as was observed du...
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Septentrio Academic Publishing
2003
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Online Access: | https://doi.org/10.7557/2.23.5.1693 https://doaj.org/article/eeb103f048e44d93a2dcbadd4a5622a2 |
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ftdoajarticles:oai:doaj.org/article:eeb103f048e44d93a2dcbadd4a5622a2 2023-05-15T15:53:29+02:00 Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment Stephen M. Arthur Kenneth R. Whitten Francis J. Mauer Dorothy Cooley 2003-04-01T00:00:00Z https://doi.org/10.7557/2.23.5.1693 https://doaj.org/article/eeb103f048e44d93a2dcbadd4a5622a2 EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/rangifer/article/view/1693 https://doaj.org/toc/1890-6729 doi:10.7557/2.23.5.1693 1890-6729 https://doaj.org/article/eeb103f048e44d93a2dcbadd4a5622a2 Rangifer, Vol 23, Iss 5 (2003) Alaska population model Rangifer tarandus caribou modeling population trend Animal culture SF1-1100 article 2003 ftdoajarticles https://doi.org/10.7557/2.23.5.1693 2022-12-31T12:56:45Z The Porcupine caribou (Rangifer tarandus granti) herd increased from approximately 100 000 animals during the 1970s to 178 000 in 1989, then declined to 129 000 by 1998. Our objective was to model the dynamics of this herd and investigate the potential that lower calf recruitment, as was observed during 1991-1993, produced the observed population changes. A deterministic model was prepared using estimates of birth and survival rates that reproduced the pattern of population growth from 1971-1989. Then, parameters were changed to simulate effects of lower calf recruitment and adult survival. Reducing recruitment for 3 years caused an immediate reduction in population size, but the population began to recover in 5-6 years. Even a dramatic temporary reduction in recruitment did not explain the continuing decline after 1995. In contrast, a slight but persistent reduction in adult survival caused a decline that closely followed the observed pattern. This suggests that survival of adults, and perhaps calves, has declined since the late 1980s. Article in Journal/Newspaper caribou Rangifer Rangifer tarandus Alaska Directory of Open Access Journals: DOAJ Articles Rangifer 23 5 123 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Alaska population model Rangifer tarandus caribou modeling population trend Animal culture SF1-1100 |
spellingShingle |
Alaska population model Rangifer tarandus caribou modeling population trend Animal culture SF1-1100 Stephen M. Arthur Kenneth R. Whitten Francis J. Mauer Dorothy Cooley Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
topic_facet |
Alaska population model Rangifer tarandus caribou modeling population trend Animal culture SF1-1100 |
description |
The Porcupine caribou (Rangifer tarandus granti) herd increased from approximately 100 000 animals during the 1970s to 178 000 in 1989, then declined to 129 000 by 1998. Our objective was to model the dynamics of this herd and investigate the potential that lower calf recruitment, as was observed during 1991-1993, produced the observed population changes. A deterministic model was prepared using estimates of birth and survival rates that reproduced the pattern of population growth from 1971-1989. Then, parameters were changed to simulate effects of lower calf recruitment and adult survival. Reducing recruitment for 3 years caused an immediate reduction in population size, but the population began to recover in 5-6 years. Even a dramatic temporary reduction in recruitment did not explain the continuing decline after 1995. In contrast, a slight but persistent reduction in adult survival caused a decline that closely followed the observed pattern. This suggests that survival of adults, and perhaps calves, has declined since the late 1980s. |
format |
Article in Journal/Newspaper |
author |
Stephen M. Arthur Kenneth R. Whitten Francis J. Mauer Dorothy Cooley |
author_facet |
Stephen M. Arthur Kenneth R. Whitten Francis J. Mauer Dorothy Cooley |
author_sort |
Stephen M. Arthur |
title |
Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
title_short |
Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
title_full |
Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
title_fullStr |
Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
title_full_unstemmed |
Modeling the decline of the Porcupine Caribou Herd, 1989-1998: the importance of survival vs. recruitment |
title_sort |
modeling the decline of the porcupine caribou herd, 1989-1998: the importance of survival vs. recruitment |
publisher |
Septentrio Academic Publishing |
publishDate |
2003 |
url |
https://doi.org/10.7557/2.23.5.1693 https://doaj.org/article/eeb103f048e44d93a2dcbadd4a5622a2 |
genre |
caribou Rangifer Rangifer tarandus Alaska |
genre_facet |
caribou Rangifer Rangifer tarandus Alaska |
op_source |
Rangifer, Vol 23, Iss 5 (2003) |
op_relation |
https://septentrio.uit.no/index.php/rangifer/article/view/1693 https://doaj.org/toc/1890-6729 doi:10.7557/2.23.5.1693 1890-6729 https://doaj.org/article/eeb103f048e44d93a2dcbadd4a5622a2 |
op_doi |
https://doi.org/10.7557/2.23.5.1693 |
container_title |
Rangifer |
container_volume |
23 |
container_issue |
5 |
container_start_page |
123 |
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1766388600046354432 |