The effects of gypsy moth infestation on the Shenandoah National Park (SNP) black bear population and habitat were studied during 1985 - 1991 by comparing radio telemetry, population, and behavioral data from preinfestation years (1982 - 1986) and years with extensive defoliation (1987 - 1991). Gypsy moth defoliation (> 60% canopy loss) increased from 546 ha in 1986 (1 % of the study area), to 2,304 ha in 1987 (4%), 6,227 ha in 1988 (12%), and 17,736 ha in 1989 (34%). Chestnut oak and red oak habitat types received the greatest defoliation; 60% and 45% of these habitat types suffered greater than 60 % canopy loss in the North and Central Districts, respectively. Infestation resulted in a 99% reduction in acorn production in defoliated stands. Maximum daily temperatures 0.5 m above the ground in defoliated stands averaged 4.7 ± 0.3 C, 4.3 ± 0.4 C, and 2.5 ± 0.3 C warmer (P < 0.01) than in nondefoliated stands during peak defoliation, refoliation, and post-refoliation periods, respectively. Bear / Ph. D.

Forty-three radio-collared black bears (Ursus americanus) captured in northwestern Virginia were released in the Mt. Rogers National Recreation Area (MRA) in southwestern Virginia, and monitored from June 1990-March 1992. Survival was 0.23 over the 22 month study; male (0.12) and female (0.37) survival rates were not different (P = 0.16). Vehicle collisions caused most of the mortality (53%), but legal harvest outside of the study area (16%) and illegal kills in the study area (11%) also were important. Female bears failed to reproduce in the first winter following translocation, but during the second winter mean litter size was 2.75 (n = 4). A computer simulation of the female segment of the translocated population at the MRA predicted 45 females in the population in 1992, but only 29 females by 2002. The instantaneous rate of increase of the simulated population was -0.05 from 1993-2002. Mean distance translocated from capture to release was 297.7 km. Eleven bears remained in their release areas (i.e., moved <10 km from release), while 32 left their release areas. The mean distance moved from release to recovery/last location was 3.6 km for the former and 48.8 km for the latter. There was no difference (P > 0.05) in the probability of remaining in or leaving the study area for either sex. Bears recovered dead were more frequently outside the study area than in the study area (P < 0.01). For bears that left their release areas, the mean direction of travel from release to recovery/last location relative to the capture location (i.e., release to capture direction = 0°) was 31° and did not differ (P > 0.05) from the homeward direction. Despite some homeward orientation, no bears returned to their capture areas during this study. / Master of Science

During June 1990 - November 1993 I measured the responses of black bears (Ursus americanus) in Shenandoah National Park (SNP), Virginia to gypsy moth (Lymantria dispar) induced oak (Quercus spp.) mortality. Oak species composed >50% of the forest canopy of SNP, and oak mortality rates ranged from 1- ≥48%. I compared black bear population dynamics, food habits, movements and habitat use to preinfestation data collected in SNP from 1982 - 1985. Scat analysis indicated that the current diet of SNP’s black bear population includes proportionally more soft mast in the fall and more soft mast and ants (Formicidae spp., P<0.0001) in the summer than did the preinfestation diet. Fewer acorns (Quercus spp. mast, P=0.03) and squawroot (Conopholis americana, P=0.01) were consumed in the fall and summer respectively. No decline in the physical condition of adult females (P=0.91), subadult males (P=0.34) or subadult females (P=0.94) was evident. Adult male physical condition declined (P=0.03) for unknown reasons. The mean age of neither female (P=0.99) nor male bears (P=0.54) was different from preinfestation data. Mean litter size - 2.25 cubs - did not differ (P=0.49) froma preinfestation mean of 2.0 cubs. Survival of radio-collared female bears was 100%, indicating that the female survival rate has not declined from a high preinfestation survival rate. Minimum cub survival rate to 1 year was 64.7%. Fall and annual home ranges of female bears were smaller (P=0.001 and P=0.002, respectively) than during preinfestation years. Use of forest cover types differed from availability during the summer (P<0.01), early fall (P<0.0001) and late fall (P<0.001) and when compared to preinfestation data. Use of stands with different levels of oak mortality was not different from availability during the summer (P=0.1) but was different during the early fall (P<0.005) and late fall (P<0.001). / Master of Science

Ecology and physiology of black bears in Great Dismal Swamp (GDS) National Wildlife Refuge and surrounding area, a forested wetland in eastern Virginia and northeastern North Carolina, were studied from April 1984 to March 1987. A total of 101 bears (71M, 30F) were captured 120 times. Males dominated the capture sample (<u>P</u>< 0.001), but age did not differ between sexes (<u>P</u>= 0.74). Mean (±SE) age was 4.2±0.3 years. Litter size (<i>x̅</i>=2.1; N=12), modal age at primiparity (4 years), and interbirth interval (slightly greater than 2 years) were indicative of good-quality habitat. Estimated annual adult survival rates were 0.84 for females and 0.58 for males. Causes of mortality included legal (outside the Refuge) and illegal harvest, vehicle collisions, depredation permit kills, research, and predation. Population density for the study area was estimatcd by 6 techniques at 0.47-0.68 bears/km², corresponding to 262-377 bears for the 555 km² study area. Demographic data suggested a stable and productive population. Three major levels of diet quality were observed in terms of crude fiber, fat, and protein. Spring diets were high in protein but moderate in crude fiber, while fall diets were low in crude protein and high in ether extract. Condition indices and several blood characteristics (e.g. total protein, albumin, HCT, hemoglobin, and RBC) were at peaks in spring and late fall and at a low during summer. Serum creatinine concentrations also varied seasonally (<u>P</u><0.001), with a peak during denning and high levels in spring and late fall, perhaps resulting from transition from and to hibernation. A urea/creatinine (U/C) ratio ≤10 was not a good indicator of the hibernating state, as 39 of 120 (32.5%) trapped, active bears had U/C ratios ≤10. Creatinine and total protein were the best indicators of the hibernating state. Albumin, HCT, hemoglobin, and RBC were the best indicators of condition during active stages, as indicated by significant (<u>P</u>< 0.1) correlations of condition indices and blood variables. Nine blood variables varied with age (<u>P</u>< 0.1). Multivariate analysis of variance and discriminant function analysis using blood variables failed to reject the hypothesis that bears cycled through 4 metabolic stages throughout the year. Results showed that metabolic shifts were tied to concomitant seasonal changes in diet quality, diet composition, and body condition, but also may have an endogenous component. Habitat and range use dynamics were described by radiotracking of 24 female and 22 male bears. Median annual range size estimates were 79.1 km² for males (<u>N</u>=10), 33.1 km² for subadult h females (<u>N</u>=7), and 21.4 km² for adult females (<u>N</u>=11). Preferred (<u>P</u>< 0.05) habitats on an annual basis were pocosins and mesic areas for females and gum-cypress and maple-coniferous stands for males. Seasonally, pocosin, gum-cypress, mesic, and disturbed areas were important for females. Bear distribution analysis indicated that roads were preferred (<u>P</u>< 0.05) during all seasons except early fall, when bears made fall excursions to feeding areas far from Swamp roads and close to the study area boundary. Range overlap was extensive for both sexes, although it appeared that females maintained exclusive ranges during spring and early summer. Denning ecology was described by monitoring 35 bears (26F, 9M). Five bears (2M, 3F) remained active throughout the winter. Den types included 14 elaborate ground nests, 11 excavated ground cavities, 2 ground-level tree cavities, 1 above-ground-level tree cavity, and l den in a stump. Females with cubs denned earlier, (<u>P</u>< 0.02) emerged later (<u>P</u>< 0.001), and denned longer (<u>P</u>< 0.001; 119 ±4 days vs. 78 ±4 days) than all other bear groups. Dry den sites did not appear to be limited. Present population management (protection from hunting and no public vehicular access) should be continued in the Refuge. The small effective population size (N=66) in 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. Maintenance and enhancement of pocosins, mature gum, oak, and disturbed habitats would benefit black bears in southeastern wetlands by providing a wide variety of natural foods throughout the year. Large den trees may not be necessary for successful denning and reproduction in certain southeastern wetlands because bears can use dense cover and microelevational factors to overwinter. Black bear conservation strategies in the Southeast are a critical need due to increasing habitat fragmentation. Six adult female black bears were maintained in captivity in Virginia from August 1987 to April 1988. Serum samples, as well as data on body weight and rectal temperatures, were collected from each bear at approximately 10-day intervals from 25 September to 30 March. Four of the six bears hibernated, not feeding for periods of 56 to 121 days (<i>x̅</i>=94 d). Rectal temperature declined in both active and hibernating bears during winter, but to a greater extent (P= 0.013) in hibernators. Average weight loss during hibernation represented 27.9% of peak body weight. Mean serum urea/creatinine (U/C) ratios were similar between physiological groups during the prehibernation phase. However, U/C ratios differed (<u>P</u>< 0.025) after the onset of hibernation. Concentrations of total serum protein, serum urea nitrogen, and serum creatinine were similarly affected by significant time-group interactions (<u>P</u>< 0.01). Alkaline phosphatase, phosphorus, sodium, and chloride changed significantly (<u>P</u>< 0.05) during the course of the experiment, without regard to physiological group. U/C ratio was a good indicator of the hibernating state, but the sensitivity of serum urea levels to diet suggests careful use of U/C ratio as a field index. Serum progesterone (P) concentrations slowly increased from 2 to 5 ng/ml during October and November, then increased 2-2.5 fold 58 ±5 days before parturition in 2 bears that produced cubs. After the implantation peak, P declined, reaching undetectable levels 1-2 days postpartum. Similar P profiles were observed in 3 of 4 bears that did not produce any observed cubs. P also was assayed in 38 active wild black bears to relate to reproductive status in the den. Changes in serum estradiol-17<i>ß</i> concentrations during gestation also were profiled. The occurrence of pseudopregnancy or early embryonic mortality in bears with elevated serum progesterone concentrations is discussed. / Ph. D.