Internal Structure of Home Ranges of Black Bears and Analyses of Home-Range Overlap

Abstract

Eight black bears (Ursus americanus) outfitted with motion-sensitive transmitter collars were radiotracked from May through December 1984 in the Pisgah Bear Sanctuary in the mountains of western North Carolina. Activities and movement patterns within areas of overlap among neighboring bears were analyzed to determine whether neighbors exhibited spatial or temporal avoidance. The distributions of locations within home ranges were clumped but bears did not use specific areas for specific activities. Home ranges overlapped extensively, and even core areas (areas of high-intensity use) overlapped. Neighboring bears often used areas of overlap for the same activities and at the same time. The clumped or patchy use of areas within home ranges requires analyses that emphasize internal structure of home ranges and not merely outlines or total-area measures.Free-ranging animals do not use all parts of their home ranges in the same way (Burt

Implications of the variable availability of seasonal foods on the home ranges of black bears, Ursus americanus, in the Sierra Nevada of California

“…Kernels are not dependent on outlying points to define their boundaries, they give insight into core activity areas, and they can exclude internal areas that were unused by the animal [44]. Since bears tend to clump their activities, rather than spread them evenly across the landscape [45], kernels are an appropriate means to represent their use patterns [8].…”

“…Kernels are not dependent on outlying points to define their boundaries, they give insight into core activity areas, and they can exclude internal areas that were unused by the animal [44]. Since bears tend to clump their activities, rather than spread them evenly across the landscape [45], kernels are an appropriate means to represent their use patterns [8].While kernels are widely preferred for estimating home ranges [46,47], there is less agreement on the appropriate smoothing factor (h) [48], which determines the kernel's width at each point in space and affects the estimate of home range size [49][50][51]. We applied three commonly used smoothing factors; least squares cross validation (lscv), reference bandwidth (h-ref) and likelihood crossvalidation (CVh) (Figure 3).…”

The role of acoustic signaling for spacing and group coordination in a nocturnal, pair‐living primate, the western woolly lemur (Avahi occidentalis)

“…To define the noncore and core area of the home ranges, the 95% (noncore) and 50% (core) Fixed Kernel method was used (Horner and Powell, 1990;Harris, 2006).…”

“…To investigate whether significant more calling positions were observed within the core compared to the non-core area, we calculated an observed versus expected Chi square test based on the number of calling positions in the respective areas. Since the 50% Kernel contour represents the 50% probability that the pair was found in the core area (Horner and Powell, 1990), the expected frequency for an equal distribution was set at 50% for the core area.…”

Detecting black bear source–sink dynamics using individual-based genetic graphs

“…Black bears have home ranges that can overlap depending on resource availability [25][26][27] and habitat quality (electronic supplementary material, figure S1). Bears in the NLP are geographically isolated as the population is bounded to the south by a matrix of unsuitable urban and agricultural habitat, and on all other sides by the Great Lakes; thus the population experiences little to no emigration and immigration that could confound results.…”