| Black bear (Ursus americanus) reproduction is once again occurring in the Big Bend region of Texas, following extirpation in the mid part of the 1900's. I monitored 10 radio-collared black bears for 15 den-years in Big Bend National Park during 1998–2000. All pregnant females ( n = 5) denned and 1 female with yearlings denned. Females with yearlings (n = 3) remained active during the 1999–2000 winter. Males (n = 4) and solitary females (n = 2) also denned. I located 10 dens of which 4 were cave dens, 3 ground dens, and 3 located in rock piles. The mean (±SE) volume of den sites was 2.2 ± 1.3 m3. Mean elevation (m) for den sites was 1,905 ± 271. The mean date of den entrance for pregnant females ( n = 5) was 24 December ± 21 days and den emergence was 21 April ± 11 days, producing a mean denning period of 118 ± 19 days. Date of den entry (P = 0.058) and duration of denning (P = 0.044) varied among sex and age classes, but date of den emergence did not differ (P = 0.522). Black bears consumed 19 different food items. Plant material composed 98%, 82%, 87%, and 88% of the diet during winter, spring, summer, and fall seasons, respectively. |
