Reliability and precision of pellet-group counts for estimating landscape-level deer density

This study provides hitherto unavailable methodology for reliably and precisely estimating deer density within forested landscapes, enabling quantitative rather than qualitative deer management. Reliability and precision of the deer pellet-group technique were evaluated in 1 small and 2 large forested landscapes. Density estimates, adjusted to reflect deer harvest and overwinter mortality, were compared with a drive count on the small landscape and with aerial counts using forward-looking infrared videography (FLIR) on the large landscapes. Estimates by 2 expert and 2 novice counters (range = 17.6 to 18.6 deer/km²) on the small landscape were not different from each other and three of the four were not different from the drive count (17.4 deer/km²). FLIR density estimates were approximately 30% lower than pellet-group estimates on the large landscapes (P < 0.04), an expected result. Precision on the small landscape was high; 95% confidence intervals for individual counters were