Some effects of winter shelter conditions on White-tailed Deer, Odocoileus virginianus, fawns

Abstract

The behavior of 11 White-tailed Deer (Odocoileus virginianus) fawns was observed from December 1970 through March 1971. The animals were maintained in individual pens under cover conditions that were naturally wooded, clear-cut, or clear-cut with an artificial windbreak. Commercial feed was supplied ad libitum and consumption measured weekly. The responses of the animals to winter climatic conditions were monitored. The deer maintained in the clear-cut pens with an artificial windbreak lost a greater percentage of their body weight, had a lower kidney fat index, and ate less relative to body weight than the deer in the other pens. Fewer opportunities for socialization by these deer was considered partially responsible for these results. Solar radiation accounted for about 28 percent of the variation in food consumption. Food intake was maximum at a mean daily ambient temperature of -15°C, minimum at -4°C and decreased below -15°C. Greater feeding and other activity occurred when skies were overcast, when the barometer was falling and when vapor pressure humidity was increasing. The location of bed sites was affected primarily by the location of deer in adjacent pens. Sites that were potentially solar exposed were selected more often on clear than overcast days. The deer in the clear-cut pens maintained trails around the periphery of their enclosures and used those portions of the trails along fences where other deer were present more than those portions where no deer were adjacent. The animals seldom moved off their trail networks when snow thickness exceeded 30 cm. Energy costs of maintenance under these free-ranging conditions were higher than those predicted from laboratory studies by a factor of 2.