Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006
Abstract Global climate change may fundamentally alter population dynamics of many species for which baseline population parameter estimates are imprecise or lacking. Historically, the Pacific walrus is thought to have been limited by harvest, but it may become limited by global warming‐induced redu...
Published in: | Marine Mammal Science |
---|---|
Main Authors: | , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2014
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1111/mms.12156 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmms.12156 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12156 |
id |
crwiley:10.1111/mms.12156 |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1111/mms.12156 2024-06-23T07:55:55+00:00 Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 Taylor, Rebecca L. Udevitz, Mark S. U.S. Geological Survey 2014 http://dx.doi.org/10.1111/mms.12156 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmms.12156 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12156 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 31, issue 1, page 231-254 ISSN 0824-0469 1748-7692 journal-article 2014 crwiley https://doi.org/10.1111/mms.12156 2024-06-06T04:23:48Z Abstract Global climate change may fundamentally alter population dynamics of many species for which baseline population parameter estimates are imprecise or lacking. Historically, the Pacific walrus is thought to have been limited by harvest, but it may become limited by global warming‐induced reductions in sea ice. Loss of sea ice, on which walruses rest between foraging bouts, may reduce access to food, thus lowering vital rates. Rigorous walrus survival rate estimates do not exist, and other population parameter estimates are out of date or have well‐documented bias and imprecision. To provide useful population parameter estimates we developed a Bayesian, hidden process demographic model of walrus population dynamics from 1974 through 2006 that combined annual age‐specific harvest estimates with five population size estimates, six standing age structure estimates, and two reproductive rate estimates. Median density independent natural survival was high for juveniles (0.97) and adults (0.99), and annual density dependent vital rates rose from 0.06 to 0.11 for reproduction, 0.31 to 0.59 for survival of neonatal calves, and 0.39 to 0.85 for survival of older calves, concomitant with a population decline. This integrated population model provides a baseline for estimating changing population dynamics resulting from changing harvests or sea ice. Article in Journal/Newspaper Odobenus rosmarus Sea ice walrus* Wiley Online Library Pacific Marine Mammal Science 31 1 231 254 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract Global climate change may fundamentally alter population dynamics of many species for which baseline population parameter estimates are imprecise or lacking. Historically, the Pacific walrus is thought to have been limited by harvest, but it may become limited by global warming‐induced reductions in sea ice. Loss of sea ice, on which walruses rest between foraging bouts, may reduce access to food, thus lowering vital rates. Rigorous walrus survival rate estimates do not exist, and other population parameter estimates are out of date or have well‐documented bias and imprecision. To provide useful population parameter estimates we developed a Bayesian, hidden process demographic model of walrus population dynamics from 1974 through 2006 that combined annual age‐specific harvest estimates with five population size estimates, six standing age structure estimates, and two reproductive rate estimates. Median density independent natural survival was high for juveniles (0.97) and adults (0.99), and annual density dependent vital rates rose from 0.06 to 0.11 for reproduction, 0.31 to 0.59 for survival of neonatal calves, and 0.39 to 0.85 for survival of older calves, concomitant with a population decline. This integrated population model provides a baseline for estimating changing population dynamics resulting from changing harvests or sea ice. |
author2 |
U.S. Geological Survey |
format |
Article in Journal/Newspaper |
author |
Taylor, Rebecca L. Udevitz, Mark S. |
spellingShingle |
Taylor, Rebecca L. Udevitz, Mark S. Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
author_facet |
Taylor, Rebecca L. Udevitz, Mark S. |
author_sort |
Taylor, Rebecca L. |
title |
Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
title_short |
Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
title_full |
Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
title_fullStr |
Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
title_full_unstemmed |
Demography of the Pacific walrus ( Odobenus rosmarus divergens): 1974–2006 |
title_sort |
demography of the pacific walrus ( odobenus rosmarus divergens): 1974–2006 |
publisher |
Wiley |
publishDate |
2014 |
url |
http://dx.doi.org/10.1111/mms.12156 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fmms.12156 https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12156 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Odobenus rosmarus Sea ice walrus* |
genre_facet |
Odobenus rosmarus Sea ice walrus* |
op_source |
Marine Mammal Science volume 31, issue 1, page 231-254 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/mms.12156 |
container_title |
Marine Mammal Science |
container_volume |
31 |
container_issue |
1 |
container_start_page |
231 |
op_container_end_page |
254 |
_version_ |
1802648731477082112 |