Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia

dc.contributor.authorRyan, Christopher W. IIen
dc.contributor.committeechairVaughan, Michael R.en
dc.contributor.committeememberHaas, Carola A.en
dc.contributor.committeememberKirkpatrick, Roy L.en
dc.contributor.departmentFisheries and Wildlifeen
dc.date.accessioned2014-03-14T20:32:16Zen
dc.date.adate1998-01-29en
dc.date.available2014-03-14T20:32:16Zen
dc.date.issued1997-12-10en
dc.date.rdate1999-01-29en
dc.date.sdate1997-12-10en
dc.description.abstractThirty-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.degreeMaster of Scienceen
dc.identifier.otheretd-02698-201736en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-02698-201736/en
dc.identifier.urihttp://hdl.handle.net/10919/31384en
dc.publisherVirginia Techen
dc.relation.haspartetd.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectUrsus americanusen
dc.subjectGeorge Washington and Jefferson National Forestsen
dc.subjectExploited populationen
dc.subjectPopulation Dynamicsen
dc.titleReproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginiaen
dc.typeThesisen
thesis.degree.disciplineFisheries and Wildlifeen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
etd.pdf
Size:
325.5 KB
Format:
Adobe Portable Document Format

Collections