Effects of thermal environment on the growth and health of white-tailed deer (Odocoileus virginianus) during summer

White-tailed deer (Odocoileus virginianus) must maintain body temperature. For nursing fawns, this is difficult because they have a high metabolic rate and cannot alter their diet like mature animals. High temperatures reduce growth rates in many species of ruminants, but the magnitude of the effect in deer is unknown. I studied the effect of summer temperature on growth and food consumption of fawns and consumption of mature bucks under 3 constraints: time-of-day feed was offered, type of feed offered, and availability of water. I randomly assigned fawns and bucks to an ambient temperature treatment or a treatment in which they could access a cooler environment (A/C treatment). For the fawn study, I recorded food intake, growth rate, behavior, and stress hormones in fecal and saliva samples. A/C fawns grew larger and had lower stress hormone levels. For the buck study, I recorded feed consumption, change in body mass, water consumption, drinking events in a day, and rumen temperature. In general, A/C deer had less variation in rumen temperature. Ambient temperature did not consistently affect intake rates, and there was only a loose correlation between consumption and rumen temperatures. These findings will assist managers understand the environmental constraints on deer and consider habitat management practices to help deer cope with high temperatures