NOCTURNAL MOVEMENTS OF WHITE-TAILED DEER - IMPLICATIONS FOR REFINEMENT OF TRACK-COUNT SURVEYS

Nocturnal radio-locations (n = 3,307) obtained from 58 radio-collared white-tailed deer (Odocoileus virginianus) from July 1988-July 1991 we re used to compare activity and movement among age-sex groups of deer within and between low- and high-density populations on the Osceola Na tional Forest and Penney Farms study sites, respectively, in northern Florida. Movements of deer on the 2 study areas differed in nocturnal rates of travel (NRT), distances between extreme nocturnal locations ( DBE), and frequencies of nocturnal activity (ACT), but not distance be tween locations at sunset and sunrise the following day (DFL) or frequ ency of road crossing (FRC). Movement and activity parameters did not differ among age-sex groups on either study site. Seasonally, FRC was the only parameter that differed on either study site. These findings suggest that population density alone may affect deer behavior regardl ess of the quantity and quality of forage and falsify the 2 major assu mptions inherent in Tyson's track-count survey method. The nocturnal r ange of individual deer was less than the assumed value of 1.6 km, and deer did not return to the same bedsite on successive days. Tyson's f ormula for assessing absolute density underestimated the size of the d eer populations by approximately 20% on both study areas, Refinements to Tyson's original formula are provided to improve the track-count me thod for estimating absolute abundance of deer.