142 Eric C. Hellgren and Michael R. Vaughan 



disjunct populations of brown bears (Ursus arctos). They attributed 

 variation to differences in system productivity or bear density. 



As part of a larger project studying black bear ecology and 

 physiology in Great Dismal Swamp, we collected body measurements 

 from live-captured black bears (Ursus americanus americanus) (Hall 

 1981). Our objectives were to provide baseline data on body measurements 

 by age for black bears in the Atlantic Coastal Plain and to produce 

 prediction equations for body mass based on morphometric measurements. 



MATERIALS AND METHODS 



We conducted research from April 1984 to August 1986 on a 

 555-km 2 study area containing the 440-km : Great Dismal Swamp 

 National Wildlife Refuge, 57.5-km 2 Dismal Swamp State Park, and 

 adjacent private land. Descriptions of the study area were reported 

 elsewhere (Hellgren and Vaughan 1988, 1989a). We captured 101 

 different bears 120 times with spring-activated cable snares during 

 April through December. Bears were immobilized with a 2:1 mixture 

 of ketamine hydrochloride and xylazine hydrochloride at a concentration 

 of 300 mg/mL administered intramuscularly at an initial dosage rate 

 of 6.6 mg/kg. Mass was measured to the nearest kg with a hanging 

 spring scale. 



We took measurements on immobilized animals to the nearest 

 mm. Body length was measured from the tip of the snout to the distal 

 end of the last caudal vertebra while the animal was in lateral recumbency. 

 Head length was measured from the tip of the nose to the occiput. 

 Neck girth was measured in the middle of the neck. Chest girth was 

 measured immediately posterior to the scapulae. Circumferences of 

 wrist and elbow (at olecranon process) also were measured. Zygomatic 

 circumference was measured anterior to the ears. The above measure- 

 ments were taken with a cloth tape pulled snug. Tail length (from 

 base of tail to distal end of caudal vertebra), ear length (from inner 

 notch to tip of pinna), forepaw and hindpaw width (greatest distance 

 across pads), and forepaw and hindpaw length (longest distance along 

 length of pads) were measured with a steel tape. Canine measurements 

 were taken with dial calipers to the nearest 0.1 mm. Upper and lower 

 canine breadths were the distance between the tips of the right and 

 left maxillary and mandibular canines, respectively. Upper and lower 

 canine lengths were measured from the gum line to the tip of the 

 canine. Anterior-posterior lengths and lingual-labial widths of upper 

 and lower canines were measured at the gum line. 



We used one-way analysis of variance to examine age differences 

 in physical characteristics within each sex. We did not analyze data 



