Masters Theses

Date of Award

8-2003

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Frank T. van Manen

Committee Members

David A. Buehler, Sammy L. King, Shih-Lung Shaw

Abstract

In 1992, U.S. Marine Corps Base Camp Lejeune (Camp Lejeune) purchased the 16,691-ha Greater Sandy Run Acquisition (GSRA) in Onslow County, North Carolina. Development and use of the GSRA for live-weapons firing and other military training has steadily increased since the land purchase. Resource managers at Camp Lejeune are interested in assessing the combined effects of military activities, forest management, roads, and the importance of natural vegetation types on black bear habitat use. My objectives were to determine black bear home range and habitat use in relation to those factors, and then synthesize spatial use patterns into a geographic information system-based habitat model. Between 2000-2001, field personnel captured 26 bears and collected 2,119 locations on 20 radio-collared bears (10 M: 10 F). Based on the 95% probability fixed kernel method, the mean annual home range was 37.2 km2 for males (n = 11) and 27.8 km2 for females (n = 12). I used 1,934 telemetry locations collected from 17 bears (7 M: 10 F) to assess habitat use with the multinomial logit form of discrete choice analysis. I compared the resource attributes of selected habitats (telemetry locations) with those available (random locations) within a spatially and temporally defined circle (i.e., "choice set"). I investigated habitat use at a daily movements scale (7-km2 choice sets) and at a more local scale (1-km2 choice sets). The analysis was based on 5 primary habitat variables (land-cover type, forest management, bum history, paved road density, and land-cover diversity) and 5 interaction terms (year, season, sex, age, and firing range activity). I used Akaike's information criterion to select the best model and used the parameter estimates to create a map of bear habitat utility values for the study area. The resource selection models performed well at both analysis scales based on model testing with independent data. Both models were robust to the effects of telemetry error. Resource selection varied depending on the spatial analysis scale. Although the importance of variables was relatively consistent for both models, parameters were more significant in the 7-km2 model. Bears selected areas with greater diversity of land-cover types only in the 7-km2 model. Land-cover was the most influential variable in both habitat models. Bottomland hardwoods exerted the greatest positive influence on bear habitat selection, followed closely by pocosin. Current levels of firing range activity did not have a measurable effect on black bear habitat selection, however, bears seemed to avoid the open land-cover type associated with the firing ranges. The density of paved roads and areas burned within 5 years had a strong negative influence on black bear habitat use at both spatial scales. I was unable to analyze the effects of forest management on black bear habitat selection because most forest stands available to bears were in the same age class. Conservation and management of pocosin and bottomland hardwoods is crucial to maintain the black bear population on the GSRA. Infrastructure development, increases in traffic volumes, and development in surrounding areas are likely to affect bear habitat use in the future; careful land-use planning and consideration of these factors will be critical for bear management on the GSRA. Although current levels of firing range activity did not influence black bear habitat use, substantial increases in the number of firing ranges and subsequent firing activities would require further examination to determine the effects on bear habitat use.

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