Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates
Using survival and reproduction data obtained from radio-tracking 23 adult female, 24 subadult female, 49 yearling, and 44 cub grizzly bears (Ursus arctos) in the Flathead River drainage of British Columbia and Montana, we estimated the finite rate of population increase [Formula: see text] from 197...
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Canadian Science Publishing
1996
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Online Access: | http://dx.doi.org/10.1139/z96-156 http://www.nrcresearchpress.com/doi/pdf/10.1139/z96-156 |
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crcansciencepubl:10.1139/z96-156 2024-04-07T07:56:22+00:00 Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates Hovey, Frederick W. McLellan, Bruce N. 1996 http://dx.doi.org/10.1139/z96-156 http://www.nrcresearchpress.com/doi/pdf/10.1139/z96-156 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 74, issue 8, page 1409-1416 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1996 crcansciencepubl https://doi.org/10.1139/z96-156 2024-03-08T00:37:42Z Using survival and reproduction data obtained from radio-tracking 23 adult female, 24 subadult female, 49 yearling, and 44 cub grizzly bears (Ursus arctos) in the Flathead River drainage of British Columbia and Montana, we estimated the finite rate of population increase [Formula: see text] from 1979 to 1994 at 1.085 ± 0.026, with ≈95% confidence limits of 1.032–1.136. Estimated annual survival rates were 0.946 ± 0.026 for adult females, 0.931 ± 0.038 for subadult females, 0.944 ± 0.039 for yearlings, and 0.867 ± 0.050 for cubs (rates for cubs and yearlings represented both sexes). The estimated annual reproduction rate and age at first parturition were 0.422 ± 0.042 female cubs per female and 6.44 ± 0.45 years, respectively. We found that uncertainty in [Formula: see text] was mostly attributable to uncertainty in survival rates (76.7%), with subadult (47.5%) and adult (21.9%) survival contributing the largest portions. These results indicated that to reduce uncertainty in [Formula: see text], further research on grizzly bears in our study area should focus on improving estimates of adult and subadult female survivorship. Other demographic variables are not as important in estimating the grizzly bear population trend in the North Fork of the Flathead River drainage. Article in Journal/Newspaper Ursus arctos Canadian Science Publishing North Fork ENVELOPE(161.250,161.250,-77.533,-77.533) Canadian Journal of Zoology 74 8 1409 1416 |
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Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Hovey, Frederick W. McLellan, Bruce N. Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Using survival and reproduction data obtained from radio-tracking 23 adult female, 24 subadult female, 49 yearling, and 44 cub grizzly bears (Ursus arctos) in the Flathead River drainage of British Columbia and Montana, we estimated the finite rate of population increase [Formula: see text] from 1979 to 1994 at 1.085 ± 0.026, with ≈95% confidence limits of 1.032–1.136. Estimated annual survival rates were 0.946 ± 0.026 for adult females, 0.931 ± 0.038 for subadult females, 0.944 ± 0.039 for yearlings, and 0.867 ± 0.050 for cubs (rates for cubs and yearlings represented both sexes). The estimated annual reproduction rate and age at first parturition were 0.422 ± 0.042 female cubs per female and 6.44 ± 0.45 years, respectively. We found that uncertainty in [Formula: see text] was mostly attributable to uncertainty in survival rates (76.7%), with subadult (47.5%) and adult (21.9%) survival contributing the largest portions. These results indicated that to reduce uncertainty in [Formula: see text], further research on grizzly bears in our study area should focus on improving estimates of adult and subadult female survivorship. Other demographic variables are not as important in estimating the grizzly bear population trend in the North Fork of the Flathead River drainage. |
format |
Article in Journal/Newspaper |
author |
Hovey, Frederick W. McLellan, Bruce N. |
author_facet |
Hovey, Frederick W. McLellan, Bruce N. |
author_sort |
Hovey, Frederick W. |
title |
Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
title_short |
Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
title_full |
Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
title_fullStr |
Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
title_full_unstemmed |
Estimating population growth of grizzly bears from the Flathead River drainage using computer simulations of reproduction and survival rates |
title_sort |
estimating population growth of grizzly bears from the flathead river drainage using computer simulations of reproduction and survival rates |
publisher |
Canadian Science Publishing |
publishDate |
1996 |
url |
http://dx.doi.org/10.1139/z96-156 http://www.nrcresearchpress.com/doi/pdf/10.1139/z96-156 |
long_lat |
ENVELOPE(161.250,161.250,-77.533,-77.533) |
geographic |
North Fork |
geographic_facet |
North Fork |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
Canadian Journal of Zoology volume 74, issue 8, page 1409-1416 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z96-156 |
container_title |
Canadian Journal of Zoology |
container_volume |
74 |
container_issue |
8 |
container_start_page |
1409 |
op_container_end_page |
1416 |
_version_ |
1795674221690486784 |