Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana
Abstract We estimated grizzly bear ( Ursus arctos ) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio‐collared females and observing their fate and reproductive performance. Our estimates of dependent cub and year...
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crwiley:10.1002/jwmg.250 2024-09-09T20:12:51+00:00 Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana Mace, Richard D. Carney, Daniel W. Chilton‐Radandt, Tonya Courville, Stacy A. Haroldson, Mark A. Harris, Richard B. Jonkel, James Mclellan, Bruce Madel, Michael Manley, Timothy L. Schwartz, Charles C. Servheen, Christopher Stenhouse, Gordon Waller, John S. Wenum, Erik 2011 http://dx.doi.org/10.1002/jwmg.250 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjwmg.250 http://onlinelibrary.wiley.com/wol1/doi/10.1002/jwmg.250/fullpdf en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor The Journal of Wildlife Management volume 76, issue 1, page 119-128 ISSN 0022-541X 1937-2817 journal-article 2011 crwiley https://doi.org/10.1002/jwmg.250 2024-06-20T04:23:23Z Abstract We estimated grizzly bear ( Ursus arctos ) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio‐collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892–0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate ( m x ) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ > 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued. © 2011 The Wildlife Society. Article in Journal/Newspaper Ursus arctos Wiley Online Library The Journal of Wildlife Management 76 1 119 128 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract We estimated grizzly bear ( Ursus arctos ) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio‐collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892–0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate ( m x ) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ > 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued. © 2011 The Wildlife Society. |
format |
Article in Journal/Newspaper |
author |
Mace, Richard D. Carney, Daniel W. Chilton‐Radandt, Tonya Courville, Stacy A. Haroldson, Mark A. Harris, Richard B. Jonkel, James Mclellan, Bruce Madel, Michael Manley, Timothy L. Schwartz, Charles C. Servheen, Christopher Stenhouse, Gordon Waller, John S. Wenum, Erik |
spellingShingle |
Mace, Richard D. Carney, Daniel W. Chilton‐Radandt, Tonya Courville, Stacy A. Haroldson, Mark A. Harris, Richard B. Jonkel, James Mclellan, Bruce Madel, Michael Manley, Timothy L. Schwartz, Charles C. Servheen, Christopher Stenhouse, Gordon Waller, John S. Wenum, Erik Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
author_facet |
Mace, Richard D. Carney, Daniel W. Chilton‐Radandt, Tonya Courville, Stacy A. Haroldson, Mark A. Harris, Richard B. Jonkel, James Mclellan, Bruce Madel, Michael Manley, Timothy L. Schwartz, Charles C. Servheen, Christopher Stenhouse, Gordon Waller, John S. Wenum, Erik |
author_sort |
Mace, Richard D. |
title |
Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
title_short |
Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
title_full |
Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
title_fullStr |
Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
title_full_unstemmed |
Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana |
title_sort |
grizzly bear population vital rates and trend in the northern continental divide ecosystem, montana |
publisher |
Wiley |
publishDate |
2011 |
url |
http://dx.doi.org/10.1002/jwmg.250 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjwmg.250 http://onlinelibrary.wiley.com/wol1/doi/10.1002/jwmg.250/fullpdf |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
The Journal of Wildlife Management volume 76, issue 1, page 119-128 ISSN 0022-541X 1937-2817 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/jwmg.250 |
container_title |
The Journal of Wildlife Management |
container_volume |
76 |
container_issue |
1 |
container_start_page |
119 |
op_container_end_page |
128 |
_version_ |
1809947471466463232 |