External Morphometries of Blaek Bears, Ursus americanus 



(Carnivora: Ursidae), in the Great Dismal Swamp 



of Virginia and North Carolina 



ERIC C. HELLGRhN 



Campus Box 218, Caesar Kleberg Wildlife Research Institute 

 Texas A&M University-Kingsville, Kingsville, Texas 78363 



And 



Michael R. Vaughan 



Virginia Cooperative Fish and Wildlife Research Unit, Virginia 



Polytechnic Institute and State University, 



Blacksburg, Virginia 24061 



ABSTRACT — We report body measurements of black bears (Ursus 

 americanus) for Great Dismal Swamp, a seasonally-flooded, forested 

 wetland in the Atlantic Coastal Plain. For most body 

 measurements, males reached adult size by 5 years of age and 

 females by 3-4 years of age. Chest girth, and zygomatic cir- 

 cumference were the best (P < 0.001) predictors of body mass 

 for both sexes. External morphometries can be used to predict 

 nutritional condition. Growth models using mass or length data 

 can be developed and growth rates compared among popula- 

 tions. Such comparisons may shed light on black bear tax- 

 onomy or habitat quality. 



Published data on black bear external morphometries, other 

 than body mass, are scanty, although common in unpublished theses. 

 Sauer (1975) reported a large data set of external measurements of 

 black bears from New York. Other publications containing data on 

 black bear morphometries include Poelker and Hartwell (1973:89- 

 104), Cherry and Pelton (1976), and Juniper (1978) from Washington, 

 Tennessee, and Quebec, respectively. 



Body morphometries and growth are important characters in the 

 study of intraspecific regional variation. In a mammal with a wide 

 distribution such as the black bear, such data may provide insights 

 into relationships among environmental factors, particularly nutrition, 

 and genetic potential. For example, mean body masses of adult (>5- 

 year-old) male black bears range from 96 kg in western Montana 

 (Jonkel and Cowan 1971) to 183 kg in Pennsylvania (Alt 1980), a 

 range mirrored by differences in reproductive rates and attributed to 

 differences in food availability (Bunnell and Tait 1981). Kingsley et 

 al. (1988) found differences in growth curves and body size in three 



Brimleyana 21:141-149, December 1994 141 



