Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend
Abstract Identifying mechanisms of population change is fundamental for conserving small and declining populations and determining effective management strategies. Few studies, however, have measured the demographic components of population change for small populations of mammals (<50 individuals...
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crwiley:10.1002/ece3.7301 2024-09-15T18:40:18+00:00 Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend McLellan, Michelle L. McLellan, Bruce N. Sollmann, Rahel Wittmer, Heiko U. Victoria University of Wellington 2021 http://dx.doi.org/10.1002/ece3.7301 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.7301 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ece3.7301 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Ecology and Evolution volume 11, issue 7, page 3422-3434 ISSN 2045-7758 2045-7758 journal-article 2021 crwiley https://doi.org/10.1002/ece3.7301 2024-08-06T04:15:08Z Abstract Identifying mechanisms of population change is fundamental for conserving small and declining populations and determining effective management strategies. Few studies, however, have measured the demographic components of population change for small populations of mammals (<50 individuals). We estimated vital rates and trends in two adjacent but genetically distinct, threatened brown bear ( Ursus arctos ) populations in British Columbia, Canada, following the cessation of hunting. One population had approximately 45 resident bears but had some genetic and geographic connectivity to neighboring populations, while the other population had <25 individuals and was isolated. We estimated population‐specific vital rates by monitoring survival and reproduction of telemetered female bears and their dependent offspring from 2005 to 2018. In the larger, connected population, independent female survival was 1.00 (95% CI: 0.96–1.00) and the survival of cubs in their first year was 0.85 (95% CI: 0.62–0.95). In the smaller, isolated population, independent female survival was 0.81 (95% CI: 0.64–0.93) and first‐year cub survival was 0.33 (95% CI: 0.11–0.67). Reproductive rates did not differ between populations. The large differences in age‐specific survival estimates resulted in a projected population increase in the larger population ( λ = 1.09; 95% CI: 1.04–1.13) and population decrease in the smaller population ( λ = 0.84; 95% CI: 0.72–0.95). Low female survival in the smaller population was the result of both continued human‐caused mortality and an unusually high rate of natural mortality. Low cub survival may have been due to inbreeding and the loss of genetic diversity common in small populations, or to limited resources. In a systematic literature review, we compared our population trend estimates with those reported for other small populations (<300 individuals) of brown bears. Results suggest that once brown bear populations become small and isolated, populations rarely increase and, even with ... Article in Journal/Newspaper Ursus arctos Wiley Online Library Ecology and Evolution 11 7 3422 3434 |
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Wiley Online Library |
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English |
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Abstract Identifying mechanisms of population change is fundamental for conserving small and declining populations and determining effective management strategies. Few studies, however, have measured the demographic components of population change for small populations of mammals (<50 individuals). We estimated vital rates and trends in two adjacent but genetically distinct, threatened brown bear ( Ursus arctos ) populations in British Columbia, Canada, following the cessation of hunting. One population had approximately 45 resident bears but had some genetic and geographic connectivity to neighboring populations, while the other population had <25 individuals and was isolated. We estimated population‐specific vital rates by monitoring survival and reproduction of telemetered female bears and their dependent offspring from 2005 to 2018. In the larger, connected population, independent female survival was 1.00 (95% CI: 0.96–1.00) and the survival of cubs in their first year was 0.85 (95% CI: 0.62–0.95). In the smaller, isolated population, independent female survival was 0.81 (95% CI: 0.64–0.93) and first‐year cub survival was 0.33 (95% CI: 0.11–0.67). Reproductive rates did not differ between populations. The large differences in age‐specific survival estimates resulted in a projected population increase in the larger population ( λ = 1.09; 95% CI: 1.04–1.13) and population decrease in the smaller population ( λ = 0.84; 95% CI: 0.72–0.95). Low female survival in the smaller population was the result of both continued human‐caused mortality and an unusually high rate of natural mortality. Low cub survival may have been due to inbreeding and the loss of genetic diversity common in small populations, or to limited resources. In a systematic literature review, we compared our population trend estimates with those reported for other small populations (<300 individuals) of brown bears. Results suggest that once brown bear populations become small and isolated, populations rarely increase and, even with ... |
author2 |
Victoria University of Wellington |
format |
Article in Journal/Newspaper |
author |
McLellan, Michelle L. McLellan, Bruce N. Sollmann, Rahel Wittmer, Heiko U. |
spellingShingle |
McLellan, Michelle L. McLellan, Bruce N. Sollmann, Rahel Wittmer, Heiko U. Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
author_facet |
McLellan, Michelle L. McLellan, Bruce N. Sollmann, Rahel Wittmer, Heiko U. |
author_sort |
McLellan, Michelle L. |
title |
Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
title_short |
Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
title_full |
Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
title_fullStr |
Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
title_full_unstemmed |
Vital rates of two small populations of brown bears in Canada and range‐wide relationship between population size and trend |
title_sort |
vital rates of two small populations of brown bears in canada and range‐wide relationship between population size and trend |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1002/ece3.7301 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ece3.7301 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/ece3.7301 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
Ecology and Evolution volume 11, issue 7, page 3422-3434 ISSN 2045-7758 2045-7758 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/ece3.7301 |
container_title |
Ecology and Evolution |
container_volume |
11 |
container_issue |
7 |
container_start_page |
3422 |
op_container_end_page |
3434 |
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1810484599412752384 |