{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/31384"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/31384","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia","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.","abstract_html":"Thirty-four (6 M, 28 F) of 93 black bears (&lt;i&gt;Ursus americanus&lt;/i&gt;) captured during summers 1995 and 1996 were equipped with radio-collars. The mean age of male and females captured was 2.5 (&lt;u&gt;n&lt;/u&gt; = 63; 2 males not aged) and 4.4 (&lt;u&gt;n&lt;/u&gt; = 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&#x27;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 (&lt;u&gt;n&lt;/u&gt; = 36). Hunting, vehicle collisions, and research each accounted for 2 of the adult and juvenile female mortalities (&lt;u&gt;n&lt;/u&gt; = 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 (&lt;i&gt;Quercus prinus&lt;/i&gt;; &lt;u&gt;n&lt;/u&gt; = 9), red oak (&lt;i&gt;Q. rubra&lt;/i&gt;; &lt;u&gt;n&lt;/u&gt; = 8), and tulip-poplar (&lt;i&gt;Liriodendron tulipifera&lt;/i&gt;; &lt;u&gt;n&lt;/u&gt; = 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 (&lt;u&gt;Z&lt;/u&gt; = -2.484, &lt;u&gt;P&lt;/u&gt; = 0.013) than tree dens. Fifty-seven percent of bears denned on public land, and we documented one instance of den reuse.","abstract_has_math":false,"creators":["Ryan, Christopher W. II"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Fisheries and Wildlife","degree_department":"Fisheries and Wildlife","school":null,"contributors":[],"advisors":[],"committee_chairs":["Vaughan, Michael R."],"committee_members":["Haas, Carola A.","Kirkpatrick, Roy L."],"year":1997,"date_issued":"1997-12-10","date_published":"1997-12-10","updated_at":"2026-07-22T22:19:39Z","subjects":["Ursus americanus","George Washington and Jefferson National Forests","Exploited population","Population Dynamics"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-02698-201736"],"render_values":[{"text":"etd-02698-201736","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/31384","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Vaughan, Michael R."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Haas, Carola A.","Kirkpatrick, Roy L."]},{"key":"dc:contributor.department","label":"Department","values":["Fisheries and Wildlife"]},{"key":"dc:creator","label":"Author","values":["Ryan, Christopher W. 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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."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Vaughan, Michael R."],"dc:contributor.committeemember":["Haas, Carola A.","Kirkpatrick, Roy L."],"dc:contributor.department":["Fisheries and Wildlife"],"dc:creator":["Ryan, Christopher W. II"],"dc:date.accessioned":["2014-03-14T20:32:16Z"],"dc:date.available":["2014-03-14T20:32:16Z","1999-01-29"],"dc:date.issued":["1997-12-10"],"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."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-02698-201736"],"dc:identifier.uri":["http://hdl.handle.net/10919/31384"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Ursus americanus","George Washington and Jefferson National Forests","Exploited population","Population Dynamics"],"dc:title":["Reproduction, Survival, and Denning Ecology of Black Bears in Southwestern Virginia"],"dc:type":["Thesis"],"thesis:degree_discipline":["Fisheries and Wildlife"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:39Z"}