Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia
dc.contributor.author | Ryan, Christopher W. II | en |
dc.contributor.committeechair | Vaughan, Michael R. | en |
dc.contributor.committeemember | Haas, Carola A. | en |
dc.contributor.committeemember | Kirkpatrick, Roy L. | en |
dc.contributor.department | Fisheries and Wildlife | en |
dc.date.accessioned | 2014-03-14T20:32:16Z | en |
dc.date.adate | 1998-01-29 | en |
dc.date.available | 2014-03-14T20:32:16Z | en |
dc.date.issued | 1997-12-10 | en |
dc.date.rdate | 1999-01-29 | en |
dc.date.sdate | 1997-12-10 | en |
dc.description.abstract | Thirty-four (6 M, 28 F) of 93 black bears (<i>Ursus americanus</i>) captured during summers 1995 and 1996 were equipped with radio-collars. The mean age of male and females captured was 2.5 (<u>n</u> = 63; 2 males not aged) and 4.4 (<u>n</u> = 28) years, respectively. The mean date of females in estrus was 24 July, and we observed one 1.5-year old female in estrus. The average age of primiparity of radio-collared females was 3.0 years; however, we documented fetuses present in a 2-year old noncollared female's reproductive tract. The average interbirth interval was 1.6 years and 95.4% of females without yearlings produced cubs. The mean litter size was 2.2 and the cub sex ratio was 1.3M:1F. Hunting, vehicle collisions, poaching, research, and euthanasia accounted for 80.5%, 5.5%, 5.5%, 5.5%, and 2.8%, respectively of the adult and juvenile male mortalities (<u>n</u> = 36). Hunting, vehicle collisions, and research each accounted for 2 of the adult and juvenile female mortalities (<u>n</u> = 6). Annual harvest rates for males in 1995 and 1996 were 36.1% and 45.5%, respectively; corresponding harvest rates for females were 0.0%, and 5.9%. Annual survival rates estimated with Kaplan-Meier for adult females, juvenile females, and cubs were 100.0%, 93.3%, and 70.3%, respectively. Maximum juvenile male survival rates were 52.0% in 1995 and 51.7% in 1996. Maximum adult male survival rates were 50.0% and 80.0% in 1995 and 1996, respectively. We monitored 31 bears for 39 bear winters with 100% of the known bears denning. Bears denned in trees (41%), rock cavities (32%), excavations (14%), snags (8%), and ground nests (5%). Chestnut oak (<i>Quercus prinus</i>; <u>n</u> = 9), red oak (<i>Q. rubra</i>; <u>n</u> = 8), and tulip-poplar (<i>Liriodendron tulipifera</i>; <u>n</u> = 1) were used as tree dens. Habitat characteristics did not differ between ground dens and tree dens; however, older bears used ground dens more frequently (<u>Z</u> = -2.484, <u>P</u> = 0.013) than tree dens. Fifty-seven percent of bears denned on public land, and we documented one instance of den reuse. | en |
dc.description.degree | Master of Science | en |
dc.identifier.other | etd-02698-201736 | en |
dc.identifier.sourceurl | http://scholar.lib.vt.edu/theses/available/etd-02698-201736/ | en |
dc.identifier.uri | http://hdl.handle.net/10919/31384 | en |
dc.publisher | Virginia Tech | en |
dc.relation.haspart | etd.pdf | en |
dc.rights | In Copyright | en |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
dc.subject | Ursus americanus | en |
dc.subject | George Washington and Jefferson National Forests | en |
dc.subject | Exploited population | en |
dc.subject | Population Dynamics | en |
dc.title | Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia | en |
dc.type | Thesis | en |
thesis.degree.discipline | Fisheries and Wildlife | en |
thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
thesis.degree.level | masters | en |
thesis.degree.name | Master of Science | en |
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