Deer management often is hindered by lack of public acceptance and confidence in census methods. Because ''seeing is believing,'' a method relying on photographic documentation could provide a powerful tool for deer managers. The purpose of our study was to determine if infrared-triggered cameras could be used for population estimation of free-ranging antlered white-tailed deer (Odocoileus virginianus) in a forested environment. Subsequently, we evaluated feasibility of using such estimates in conjunction with demographic ratios for population estimation. We used infrared-triggered cameras and monitors to census white-tailed deer on Longleaf Farms, a 4,047-ha area in Amite County, Mississippi. Two 14-day censuses were conducted, 1 in February 1992 and 1 in February 1993. Passive infrared monitors that triggered automatic cameras were used to photograph deer; previously marked deer in the photographs provided recapture data. We derived population estimates from photographs using Lincoln-Petersen Index estimates from marked and unmarked animals, and from a separate technique we termed the camera estimate. The camera estimate was calculated by determining the total numbers of branch-antlered bucks, spike bucks, does, and fawns in photographs, then determining the number of individually identifiable branch-antlered bucks and, from ratios, the number of spike bucks, does, and fawns. Camera densities tested included 65, 130, and 259 ha per camera. With the highest camera density (1/65 ha), 30 of 30 collared deer (100%) were recaptured in 1992 and 30 of 34 (88.2%) were recaptured in 1993. Camera estimates using ratios of spikes, does, and fawns to branch-antlered bucks yielded population estimates of 715 and 580 deer for 1992 and 1993, respectively. Lincoln-Petersen estimates yielded 727 and 573 deer for the same respective periods. However, at different camera densities, the sex ratios and Lincoln-Petersen Index population estimates differed significantly (P less than or equal to 0.001). There was an inverse relationship between camera density and Lincoln-Petersen Index population estimates. Percent females increased as camera density increased, indicating higher recapture estimates of males over females at low camera densities. Although population and sex-ratio estimates differed among camera-station densities, infrared-triggered cameras are useful tools to census deer in forested environments. Minimally, they provide estimates of adult bucks present. Cost of a 14-day census amortized over a 5-year equipment life expectancy ranged $0.37-1.29/ha/year depending on camera coverage.
