Effects of Deer Density and Land Use on Mass of White-Tailed Deer

摘要

Local and regional land use changes, such as the expansion of cropland for cellulosic biofuels, and the population density of white-tailed deer can affect the health and body mass of white-tailed deer Odocoileus virginianus. We collected hunterharvest data for 1,731 white-tailed deer from DeSoto National Wildlife Refuge in eastern Nebraska and western Iowa from 2003 to 2010. We used linear mixed-effects models and information theoretic methods to estimate effects of density of white-tailed deer and proportion of total landcover area converted from cropland to cool- or warm-season grassland on body mass of white-tailed deer. Density of white-tailed deer at DeSoto National Wildlife Refuge ranged from 36.5 to 50.6 deer/km2, and the proportion of landcover at DeSoto National Wildlife Refuge that remained cropland each year ranged from 14.9 to 23.2%. Body mass was inversely related to population density (21.4 kg/5.5 deer/km2) and proportion of cropland (21.3 kg/3.1% conversion of total land area from cropland to grassland). We used auxiliary harvest data collected at Boyer Chute National Wildlife Refuge to validate our models and found our models performed well. We estimate densities of white-tailed deer must be reduced by 1.7 (SE = 0.6) deer/km2 for every 1% change in total landcover from cropland to grassland in order for white-tailed deer to maintain body mass. Our results indicate increased harvest of white-tailed deer, resulting in a reduction in population density, may offset negative effects that a decline in the amount of available cropland could have on the body mass and health of white-tailed deer.