Comparing Methods of Estimating Fecal Pellet-Group Density in Woodlots of the Midwest United States

Abstract

Fecal-pellet surveys provide density estimates of pellet groups, which offer a quick and reliable index of population densities for white-tailed deer Odocoileus virginianus and other wildlife species. Comparisons of differing fecal-pellet survey methodologies have previously shown that they vary in the precision. However, these comparisons have been made outside of the United States in regions with lower white-tailed deer densities. In this study, we compared pellet-group density estimates and precisions from line-transects, quadrat sampling, and strip-transects. At each site, three observers surveyed simultaneously with each being responsible for one method. Like other studies, we found that each method produced similar estimates of pellet-group density, but quadrat sampling produced the most precise estimates. Furthermore, all three methods suggested that the central region of Indiana had both the highest pellet-group density and the highest precision. Thus, suggesting that pellet groups may be more homogenously distributed in areas with higher white-tailed deer densities, which may increase the precision of all methods. Our results suggest that quadrat sampling may be the most effective method for estimating pellet-group densities within woodlots of the Midwest United States, and that precision may increase in areas with higher white-tailed deer densities. This study not only improves deer management within the Midwest United States but provides guidelines for other studies to potentially advance the conservation and management of other species.