Masters Theses

Date of Award

8-1998

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Michael R. Pelton

Committee Members

Joe Clark, Ralph Dimmick

Abstract

Increases in the number of black bear (Ursus americanus) sightings, nuisance complaints, and bear-vehicle collisions on Alligator River National Wildlife Refuge (ARNWR or refuge) and Dare County Bombing Range (DCBR), North Carolina prompted sportsmen and local residents to request that the United States Fish and Wildlife Service and the North Carolina Wildlife Resources Commission open a bear hunting season on ARNWR and the DCBR. Data on reproduction and survival were needed to determine if the population could sustain a harvest. Data on denning chronology were needed to determine potential effects of denning on harvest.

I estimated reproductive rates by examining family groups in natal dens and after den emergence and by examining reproductive tracts for the presence of corpora lutea and placental scars. Mean litter size was 2.1 (SD = 0.8) and ranged from 1 to 3 based on cub observations. Mean litter size of females ≥5 years old was 2.7 (SD = 0.5) and 2.5 (SD = 0.7) based on corpora lutea and placental scar counts, respectively.

Females on the Alligator River National Wildlife Refuge and Dare County Bombing Range reproduced earlier than many other black bear populations in North America. Successful breeding, indicated by the presence of corpora lutea, occurred in females ≥1.5 years old. Eighty-one percent of tracts from 2.5-year-old females contained corpora lutea. Placental scars were present in tracts from females ≥2.75 years old. By age 4, 50% of the tracts contained corpora lutea and 50% contained placental scars.

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