Masters Theses

Date of Award

5-1993

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Michael R. Pelton

Committee Members

Joe Clark, Edward R. Buckner, Ralph Dimmick

Abstract

Fifteen black bears (Ursus americanus) were captured 24 times on Marine Corps Base Camp Lejeune, North Carolina, during 1988 and 1989. Females dominated the capture sample, but age did not differ between the sexes (P=0.31). No subadult males were captured during the study. Mean litter size was 2.2 (n=6) with females attaining primiparity at age 4. Breeding may occur at age 3; den observations-and teat development suggested previous parturition in a four-yearold. Estimated annual survival rates were 0.77 for males, 0.69 for females, and 0.53 for cubs. Causes of mortality included vehicle collisions (n=S), research (n=l), and legal kill (n=l; outside the study area). Population density for the study area was estimated by 4 techniques at 0.16-0.30 bears/km2, or 21-40 bears. Twenty three bears were known to inhabit the base as residents or seasonal migrants.

Denning ecology was described for 14 bears (12F, 2M). Winter activity was recorded for 5 of 7 bears in 1989 and 3 of 7 bears in 1990. Two bears (1 adult male, 1 subadult female) used multiple den locations. Bears denned exclusively on ground nests in three habitat types; pocosin (n=ll), lowland pine-hardwood (n=2), and an area of forest regeneration (n=l). Vegetation density at the hibernacula (x=94%) was greater (P<0.001) than random locations. Prescribed burns resulted in 4 den abandonments (50% of all human disturbance) and overall den abandonment was high (36%). Parturient females generally denned earlier (Dec. 23 ±10.4d) .than all other bear groups.

Male home ranges (60.5 km2) were larger on average than female ranges (20.4 km2). Annual home range size for solitary females, subadult females, and females with cubs were not different (P=0.34). Annual home range overlap was extensive for females; considerable overlap was present between males and females during both years of the study.

Habitat utilization was-determined by plotting telemetry locations on Camp Lejeune Forest Compartment maps. Bears used pocosin habitat more than expected based on random availability during all seasons except late summer. Mesic and xeric hardwoods were important habitats during late summer and early fall with the latter also disproportionately selected in late fall. Pine-hardwood habitats were used during summer and early fall; pure pine habitats were avoided throughout the year. Salt marsh and the landfill were selected habitats during late summer. Use of artificial foods was opportunistic in nature. Female bears were located farther from Class I roads during late fall than any other season. The distribution of bears to Class I roads suggested a relationship to habitat position. Bears were located closer to Class II roads than Class I roads throughout the year.

Factors indirectly associated with the military mission, such as increased traffic volumes and urban development off Base property, impact the black bear population to a greater degree than military training itself. Abnormally high mortality rates for females and lack of dispersal information for subadult males indicates a need for further study. Genetic relationships between resident bears on Camp Lejeune and bears in the surrounding areas of Great Sandy Run Pocosin, Hoffman Forest, and Croatan National Forest warrant investigation to determine the degree of isolation and genetic variability within and among black bear populations in southeastern North Carolina.

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