Natal dispersal of grizzly bears
We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and...
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Language: | English |
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Canadian Science Publishing
2001
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Online Access: | http://dx.doi.org/10.1139/z01-051 http://www.nrcresearchpress.com/doi/pdf/10.1139/z01-051 |
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crcansciencepubl:10.1139/z01-051 2024-06-23T07:57:22+00:00 Natal dispersal of grizzly bears McLellan, Bruce N Hovey, Frederick W 2001 http://dx.doi.org/10.1139/z01-051 http://www.nrcresearchpress.com/doi/pdf/10.1139/z01-051 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 79, issue 5, page 838-844 ISSN 0008-4301 1480-3283 journal-article 2001 crcansciencepubl https://doi.org/10.1139/z01-051 2024-05-24T13:05:49Z We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and farther still by 4 years of age. Dispersal of both sexes was a gradual process, occurring over 14 years. From the locations of death, or last annual ranges, it was estimated that 18 males dispersed 29.9 ± 3.5 km (mean ± SE) and 12 females dispersed 9.8 ± 1.6 km. Eleven of these males dispersed the equivalent of at least the diameter of 1 adult male home range, whereas only 3 of the females dispersed at least the diameter of 1 adult female home range. The longest dispersals recorded were 67 km for a male and 20 km for a female. Because the social system consists of numerous overlapping home ranges of both sexes, long dispersal distances may not be required to avoid inbreeding or competition with relatives. Simple models suggest that 61% of the ranges of brother and sister pairs would not overlap, but the home range of every daughter would overlap her father's range. The home range of an estimated 19 ± 4 (mean ± SD) adult males, however, would overlap at least a portion of each female's range, thereby reducing the chance of a female mating with her brother or father. Understanding the dispersal behaviour of grizzly bears is essential for developing conservation strategies. Our results suggest that meta-population reserve designs must provide corridors wide enough for male grizzly bears to live in with little risk of being killed. Article in Journal/Newspaper Ursus arctos Canadian Science Publishing Canadian Journal of Zoology 79 5 838 844 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
description |
We studied natal dispersal of grizzly bears (Ursus arctos), a solitary nonterritorial carnivore with a promiscuous mating system, between 1979 and 1998. Dispersal distances for 2-year-olds did not differ between males and females, but by 3 years of age, males had dispersed farther than females, and farther still by 4 years of age. Dispersal of both sexes was a gradual process, occurring over 14 years. From the locations of death, or last annual ranges, it was estimated that 18 males dispersed 29.9 ± 3.5 km (mean ± SE) and 12 females dispersed 9.8 ± 1.6 km. Eleven of these males dispersed the equivalent of at least the diameter of 1 adult male home range, whereas only 3 of the females dispersed at least the diameter of 1 adult female home range. The longest dispersals recorded were 67 km for a male and 20 km for a female. Because the social system consists of numerous overlapping home ranges of both sexes, long dispersal distances may not be required to avoid inbreeding or competition with relatives. Simple models suggest that 61% of the ranges of brother and sister pairs would not overlap, but the home range of every daughter would overlap her father's range. The home range of an estimated 19 ± 4 (mean ± SD) adult males, however, would overlap at least a portion of each female's range, thereby reducing the chance of a female mating with her brother or father. Understanding the dispersal behaviour of grizzly bears is essential for developing conservation strategies. Our results suggest that meta-population reserve designs must provide corridors wide enough for male grizzly bears to live in with little risk of being killed. |
format |
Article in Journal/Newspaper |
author |
McLellan, Bruce N Hovey, Frederick W |
spellingShingle |
McLellan, Bruce N Hovey, Frederick W Natal dispersal of grizzly bears |
author_facet |
McLellan, Bruce N Hovey, Frederick W |
author_sort |
McLellan, Bruce N |
title |
Natal dispersal of grizzly bears |
title_short |
Natal dispersal of grizzly bears |
title_full |
Natal dispersal of grizzly bears |
title_fullStr |
Natal dispersal of grizzly bears |
title_full_unstemmed |
Natal dispersal of grizzly bears |
title_sort |
natal dispersal of grizzly bears |
publisher |
Canadian Science Publishing |
publishDate |
2001 |
url |
http://dx.doi.org/10.1139/z01-051 http://www.nrcresearchpress.com/doi/pdf/10.1139/z01-051 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
Canadian Journal of Zoology volume 79, issue 5, page 838-844 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z01-051 |
container_title |
Canadian Journal of Zoology |
container_volume |
79 |
container_issue |
5 |
container_start_page |
838 |
op_container_end_page |
844 |
_version_ |
1802650981892096000 |