Aspects of Reproduction and Cub Survival in a Hunted Population of Virginia Black Bears
dc.contributor.author | Echols, Kim Needham | en |
dc.contributor.committeechair | Vaughan, Michael R. | en |
dc.contributor.committeemember | Kirkpatrick, Roy L. | en |
dc.contributor.committeemember | Haas, Carola A. | en |
dc.contributor.committeemember | Hallerman, Eric M. | en |
dc.contributor.department | Fisheries and Wildlife Sciences | en |
dc.date.accessioned | 2011-08-06T16:06:21Z | en |
dc.date.adate | 2000-08-17 | en |
dc.date.available | 2011-08-06T16:06:21Z | en |
dc.date.issued | 2000-06-09 | en |
dc.date.rdate | 2001-08-17 | en |
dc.date.sdate | 2000-08-15 | en |
dc.description.abstract | We 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.degree | Master of Science | en |
dc.format.medium | ETD | en |
dc.identifier.other | etd-08152000-19430055 | en |
dc.identifier.sourceurl | http://scholar.lib.vt.edu/theses/available/etd-08152000-19430055 | en |
dc.identifier.uri | http://hdl.handle.net/10919/10108 | en |
dc.publisher | Virginia Tech | en |
dc.relation.haspart | KimsETD.pdf | en |
dc.rights | In Copyright | en |
dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
dc.subject | Reproduction | en |
dc.subject | Virginia | en |
dc.subject | implants | en |
dc.subject | subcutaneous | en |
dc.subject | cub survival | en |
dc.subject | Ursus americanus | en |
dc.subject | black bears | en |
dc.title | Aspects of Reproduction and Cub Survival in a Hunted Population of Virginia Black Bears | en |
dc.type | Thesis | en |
thesis.degree.discipline | Fisheries and Wildlife Sciences | 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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