Basal Metabolism of White-Tailed Deer: A Pilot Study

Abstract

Numerous investigations of the nutritional requirements of deer, and the value of their natural foods, have been undertaken in the interests of habitat improvement or estimation of carrying capacity (Maynard et al., 1935; Forbes et al., 1941; Davenport, 1939; Einarsen, 1946; French et al., 1955; Smith, 1950; Bissell et al., 1955; Bissell and Strong, 1955). Results of digestion trials on northern white-tailed deer (Odocoileus virginianus borealis) conducted over four consecutive years, 1953-1957, by the New Hampshire Fish and Game Department, in cooperation with the University of New Hampshire, differed widely between individuals and groups, presumably because of differences in temperament, physical condition, or degree of tameness (Silver and Colovos, 1957). Basal requirements are characteristic of a species within fairly narrow limits. Total requirements, however, may be greatly modified by numerous internal and external factors including growth, size, body covering, pregnancy, lactation, food consumption, plane of nutrition, activity, fright, and environmental temperature. Wild animals live under more widely varying conditions than domestic stock; it is seldom possible to secure adequate consumption of food; the emotional impact of capture, confinement and handling is unpredictable, and often violent and disastrous. Normal existence may or may not impose equal stresses, but these are certainly not the same, nor comparable to, those associated with feeding trials. In the case of large wild animals, the value of nutrition balances is questionable unless supported by data on basal metabolism. Basal metabolic rate, or basal metabolism, is the heat production of a resting animal in a thermally neutral environment and in the postabsorptive state without any stimulating effect of food. Considerable work has been done by Benedict (1938) and Brody (1945) on comparison of the metabolism of different species. The work of neither, however, included a study of the metabolic rate of deer. In fact, very few wild animals have been studied because it is difficult to make measurements under the prerequisite physical conditions. The principal difficulty encountered is, naturally, in inducing the animals to relax.