Den Tree Avaliability and Denning Success of Black Bears on Industrial Forest Lands and National Forest Lands in Virginia and West Virginia

Abstract

During 1999-2001, potential den trees and denning success of black bears was investigated on industrial forest lands and national forest lands in Virginia and West Virginia. One hundred and fifty seven potential den trees were found on five study areas, 135 on national forest lands and 22 on the industrial forest lands. Twenty-seven hollow potential den trees were found, 22 on national forest lands and 5 on industrial forest lands. Densities of potential den trees ranged from 12.5/km2 to 437.5/km2 on the national forest lands and on the industrial forest lands the densities ranged from 0-187.5/km2. There were significantly higher densities (F1, 69=5.86, P=0.0181) of potential den trees on the national forest land than on the industrial forest land. There were also significantly (F=2, 68=7.86 P=0.0008) higher densities of hollow potential den trees based on the stand age class. Denning success for females expected to have cubs was 98% (n=46) in tree dens on national forest lands and 100% (n=8) on industrial forest lands. Denning success for females expected to have cubs was 76% (n=55) in ground dens on national forest lands and 80% (n=5) in ground dens on industrial forest lands. Females expected to have cubs on the national forest lands had an overall denning success of 89% (n=80) and on industrial forest lands there was overall, 92% (n=13) denning success. Chi-square tests showed that abandonment of dens by bears was significantly higher (x2=19.02, 1df) in ground dens than in tree dens. Litter sizes were not different from national forest lands and industrial forest lands (t=-0.36, 44df, P=0.84). The mean litter sizes on the national forest lands was 2.55 (SE=0.16) cubs per litter and on the industrial forest land 2.4 (SE=0.22) cubs per litter.