Aspects of Reproduction and Cub Survival in a Hunted Population of Virginia Black Bears

dc.contributor.authorEchols, Kim Needhamen
dc.contributor.committeechairVaughan, Michael R.en
dc.contributor.committeememberKirkpatrick, Roy L.en
dc.contributor.committeememberHaas, Carola A.en
dc.contributor.committeememberHallerman, Eric M.en
dc.contributor.departmentFisheries and Wildlife Sciencesen
dc.date.accessioned2011-08-06T16:06:21Zen
dc.date.adate2000-08-17en
dc.date.available2011-08-06T16:06:21Zen
dc.date.issued2000-06-09en
dc.date.rdate2001-08-17en
dc.date.sdate2000-08-15en
dc.description.abstractWe measured black bear (Ursus americanus) reproduction and cub survival during 1994 - 1998, and 1995 - 1999, respectively, in the George Washington and Jefferson National Forests in Virginia to determine age-specific and overall cub production and cub survival. We observed females in estrus between 6 June and 22 August; the mean date of estrus was 17 July. Ages of primiparity ranged between 3 and 5 years with an average of 3.36 years (n=11, SE=0.15). Average litter size for 1995 - 1998 was 2.32 cubs/litter (SE=0.11, n=53) and 85.7% of available females ≥ age 4 (those not accompanied by cubs) reproduced in a given den season. We monitored 98 (48M:50F) black bear cubs equipped with expandable radio-collars (Higgins 1997) or radio transmitters implanted subcutaneously between 1995 and 1999 to estimate cub survival. Kaplan-Meier staggered entry analysis provided 306-day survival rates for 82 cubs. The survival estimates for males and females were 73% (0.49, 0.96) and 91% (0.80, 1.00), respectively. The overall 306-day survival rate for all cubs was 81% (0.67,0.94) using Kaplan-Meier and 76% (0.63, 0.92) using Heisey-Fuller (Mayfield) methods. We also evaluated the utility of radio transmitters implanted subcutaneously in 42 (21M:21F) wild black bear (Ursus americanus) cubs from 2 study areas in Virginia between 1996 and 1999 to monitor first year cub survival. More than 64% (27 of 42) of the implants fell out prematurely (2-198 days), and 16.6% (7 of 42) failed for unknown reasons. Less than 5% (2 of 42) of these cubs denned wearing failed implants, and 9.5% (4 of 42) experienced mortality less than 1 month after implant surgery. About 9.5% (4 of 42) of implanted black bear cubs wore working transmitters through to the following den season.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.otheretd-08152000-19430055en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08152000-19430055en
dc.identifier.urihttp://hdl.handle.net/10919/10108en
dc.publisherVirginia Techen
dc.relation.haspartKimsETD.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectReproductionen
dc.subjectVirginiaen
dc.subjectimplantsen
dc.subjectsubcutaneousen
dc.subjectcub survivalen
dc.subjectUrsus americanusen
dc.subjectblack bearsen
dc.titleAspects of Reproduction and Cub Survival in a Hunted Population of Virginia Black Bearsen
dc.typeThesisen
thesis.degree.disciplineFisheries and Wildlife Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen
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