Home Range and Activity Patterns by Gray Foxes. 



Urocyon cinereoargenteus (Carnivora: Canidae), in 



East Tennessee 



Cathryn H. Greenberg 1 

 Ecology Program, Knoxville, Tennessee 37901-1071 



AND 



Michael R. Pelton 



Department of Forestry, Wildlife and Fisheries, 

 Knoxville, Tennessee 37901-1071 



ABSTRACT — We determined home-range size, spatial distribution, 

 and activity patterns of gray foxes (Urocyon cinereoargenteus) 

 (N = 10) between September 1986 and August 1987 in east 

 Tennessee. Average annual home-range size was 3.97 ± 1.51 

 (x ± SE) km : . There were no significant differences in home- 

 range size between sexes (females 3.67 ± 1.54; males 4.27 ± 

 1.59 km : ) or age groups (adults 4.41 ± 1.46; subadults 3.20 

 ± 1.62 km 2 ). Home-range sizes were similar in three reproductive 

 seasons and in seasons of predominantly fruit (presumably abundant) 

 and predominantly flesh (presumably more scarce) diets. Home 

 ranges of adult male-female pairs and subadults coincided, suggesting 

 monogamy and exclusive area utilization by family groups. We 

 observed lower sunrise and/or daylight activity levels during breeding 

 and flesh diet seasons, and in months of low foliar cover. 



The relationship of body size, metabolic needs, and dietary trophic 

 level to home-range size is well known. Relative to body size, flesh- 

 eaters have larger home ranges than plant-eaters, presumably due to 

 decreasing food base with ascending trophic level (McNab 1963). 

 However, most studies relating home-range size to trophic level are 

 based on interspecific comparisons. 



Intraspecifically, seasonal shifts in home-range size appear to be 

 negatively correlated to food availability (Nicholson 1982). Sex, age, 

 and reproductive cycle (MacDonald 1980), population density (Trapp 

 and Hallberg 1975), inter- or intraspecific competition, and habitat 

 quality and dispersion (MacDonald 1980) are also thought to play a 

 role in affecting home-range size. 



Most studies indicate that gray foxes are nocturnally active (Yearsley 

 and Samuel 1980, Nicholson 1982, Haroldson and Fritzell 1984). However, 



1 Present address: United States Department of Agriculture Forest Service, South- 

 eastern Forest Experiment Station, P.O. Box 14524, Gainesville, Florida 32604. 



Brimleyana 21:131-140, December 1994 131 



