Progress 10/01/05 to 09/30/10
Outputs
OUTPUTS: Long-term research begun in 1981 on the ecology and behavior of the black bear (Ursus americanus) population in the Pisgah Bear Sanctuary in the mountains of western North Carolina continued through 2009 with analyses of data collected through 2002 and publication of papers. We analyzed bears vital rates and population growth of black bears and showed that bears under different hunting regimes differ in the age-specific vital rates that are most important. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Long-term research begun in 1981 on the ecology and behavior of the black bear (Ursus americanus) population in the Pisgah Bear Sanctuary in the mountains of western North Carolina continued through 2009 with analyses of data collected through 2002 and publication of papers. We analyzed bears vital rates and population growth of black bears and showed that bears under different hunting regimes differ in the age-specific vital rates that are most important.
Publications
- Mitchell, M S, L B Pacifici, J B Grand, & R A Powell. 2009. Contributions of vital rates to growth of a protected population of American black bears. Ursus 20: 77-84.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Long-term research begun in 1981 on the ecology and behavior of the black bear (Ursus americanus) population in the Pisgah Bear Sanctuary in the mountains of western North Carolina continued through 2008 with analyses of data collected through 2002 and publication of papers. We analyzed bears' movements following capture, and blood samples and physical measurements collected during handling. We modelled home ranges of animals on a patchy landscape, similar to the landscapes occupied by bears. Because home ranges estimated from animal locations are largely continuous in space, the resource-bearing patches selected by an animal from a fragmented distribution of patches could be difficult to discern. PARTICIPANTS: Principal Investigator: Roger A Powell TARGET AUDIENCES: The scientific community, wildlife managers, environmental organizations PROJECT MODIFICATIONS: Funding has not become available for genetic analyses. Therefore, all aspects of the project dependent on genetic analyses have been put been suspended until funding becomes available.
Impacts
Analyses of bears' movements following capture show that activity is depressed for about 2 weeks before returning to normal levels. Struggling in snares can lead to muscle injury and frequent capture can retard growth by young bears. We modelled home ranges of animals on a patchy landscape, similar to the landscapes occupied by bears. The potential bias of including unselected, largely irrelevant patches in the field estimates of home ranges of animals can be high, particularly for home range estimators that assume uniform use of space within home range boundaries. Thus, inferences about the habitat relationships that ultimately define an animal's home range can be misleading where animals occupy landscapes with patchily distributed resources.
Publications
- Cattet, M, J Boulanger, G Stenhouse, R A Powell & M J Reynolds-Hogland. 2008. An evaluation of long-term capture effects in ursids: implications for wildlife welfare and research. Journal of Mammalogy 89: 973-990.
- Mitchell, M S & R A Powell. 2008. Estimated home ranges can misrepresent habitat relationships on patchy landscapes. Ecological Modelling 216: 409-414.
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Progress 10/01/06 to 09/30/07
Outputs
Long-term research begun in 1981 on the ecology and behavior of the black bear (Ursus americanus) population in the Pisgah Bear Sanctuary in the mountains of western North Carolina continued through 2007. Analyses of vegetation data show that berry plants that provide important foods for bears are most abundant and produce the most berries during the 10 years following logging, then drop to very low levels for >60 years, and then rise to intermediate levels thereafter. Bears selected den sites far from gravel roads, on steep slopes, and at high elevations relative to what was available. Selection of den sites did not differ by sex or age, but did differ for bears of different reproductive status. Adult females with cubs preferred to den in areas that were relatively far from gravel roads while adult females without cubs did not.
Impacts
Because black bears are the only bears with high population sizes, broad distributions, and are not endangered, the information gained from this research can be applied to bear populations requiring conservation management. In addition, because all mammals have the potential for inbreeding and kin recognition, the understanding gained about home ranges can be applied to understand other mammals.
Publications
- Reynolds-Hogland, M.J., Mitchell, M.S., and Powell, R.A. 2006. Spatio-temporal Availability of Soft Mast in Clearcuts in the Southern Appalachians. Forest Ecology and Management 237: 103-114.
- Mitchell, M.S., and Powell, R.A. 2007. The optimal use of resources structures home ranges and spatial distribution of black bears. Animal Behaviour 74: 219-230.
- Reynolds-Hogland, M.J., Mitchell, M.S., Brown, D. and Powell, R.A. 2007. Den site selection by black bears in the Southern Appalachians. Journal of Mammalogy 88:1062-1073.
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Progress 10/01/05 to 09/30/06
Outputs
Long-term research begun in 1981 on the ecology and behavior of the black bear (Ursus americanus) population in the Pisgah Bear Sanctuary in the mountains of western North Carolina continued through 2006. Analyses of data show that the foraging behavior of bears during their active season is optimal and that foraging rules used by bears are the same as those used by small passerine birds foraging during each day in winter to be able to survive a night-time fast. Although trapping methods used in this research meet accepted standards for animal welfare, being trapping still affects foraging behavior, and probably social behavior, of black bears for at least 2 weeks following capture.
Impacts
Because black bears are the only bears with high population sizes, broad distributions, and are not endangered, the information gained from this research can be applied to bear populations requiring conservation management. In addition, because all mammals have the potential for inbreeding and kin recognition, the understanding gained about home ranges can be applied to understand other mammals.
Publications
- Reynolds-Hogland, M. J., M. S. Mitchell, and R. A. Powell. 2007. Spatio-temporal Availability of Soft Mast in Clearcuts in the Southern Appalachians. Forest Ecology and Management
- Mitchell, M. S., and R. A. Powell. 2007. The optimal use of resources structures home ranges and spatial distribution of black bears. Animal Behaviour.
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