Demographic Analysis of a Black Bear Population in the Great Dismal Swamp
Hellgren EC and Vaughan MR. 1989. Demographic Analysis of a Black Bear Population in the Great Dismal Swamp. The Journal of Wildlife Management. 53(4):969-977
During April 1984-August 1986, 101 black bears (Ursus americanus) (71 M, 30 F) were captured 120 times in the Great Dismal Swamp (GDS) National Wildlife Refuge (NWR) and surrounding area, a forested wetland in eastern Virginia and northeastern North Carolina. Males dominated the capture sample (P 9 years old were male (n = 5). Litter size (n = 12, x̄ = 2.1), suspected modal age at primiparity (4 yr), and interbirth interval (approx 2 yr) were indicative of good-quality habitat. Estimated annual survival rates were 0.87 for females (≥1.5 yr) and 0.59 for males (≥2.5 yr). Causes of mortality included legal and illegal harvest, vehicle collisions, depredation permit kills, research, and intraspecific predation. Estimated bear density was 0.52-0.66 bears/km2, corresponding to 286-368 bears for the 555-km2 study area. Present population management (protection from hunting and no public vehicular access) should be continued in the GDSNWR. The small effective population size (Ne = 56) in the GDS indicated the need for study of dispersal and genetics in the GDS and other southeastern wetland populations to determine the degree of isolation and extent of genetic variability. Black bear conservation strategies in the southeast are critical due to increasing habitat fragmentation.
- Type
- Journal Article
- Authors
- Hellgren, Eric; Vaughan, Michael
- Units
- BIBE
- Keywords
- Carnivora, Demography, Great Dismal Swamp VA & NC, Mammalia, population analysis, Uresus americanus, Ursidae