White-tailed deer body and antler size vary widely across their geographic distribution, and managers are interested in factors associated with larger morphometrics. Previous work has considered landscape and temperature effects on morphology, but there is limited information on how these factors interact with site-specific forage availability to determine body and antler size. We collected body mass, antler size, and site-specific growing-season forage availability from 35 properties across 21 eastern U.S. states. Average female body mass increased by 1.7 pounds for every 1˚F decrease in average annual temperature and increased by 3.5 pounds for every 10-percentage point increase in landscape crop coverage. Mature male antler size also correlated with temperature and crop coverage, with antler size increasing by 1.1 inches for every 1˚F decrease in temperature and increasing by 2.8 inches for every 10-percentage point increase in crop coverage. After controlling for landscape effects, adult female body mass increased by 0.13 pounds for every 1 deer day/acre increase in site-specific nutritional carrying capacity based on a 0.3% phosphorus constraint (PNCC). Mature male antler size was marginally correlated with PNCC as well, with antler size increasing by 0.1 inch for every 1 deer day/acre increase in PNCC. Our results indicate climate and landscape variables promoting growing-season forage have a consistent influence on morphology, and we found support for site-specific forage availability influencing female body and male antler size. We recommend managers increase site-specific nutritional availability within the context of landscape-level nutrition to help shape expectations if increasing deer morphometrics is an objective.
