Seasonal Energy Metabolism of Adult Moose

Abstract

Energy expenditure of tame adult moose (Alces alces gigas) was measured at approximately monthly intervals for a period of 13 months using an indirect respiration chamber. Mean heat production (HP) in summer (May-Sep) exceeded that in winter (Nov-Mar) by a factor of 1.4. Fasted HP in moose while lying down averaged 394 kJ/kgo7s/day in winter and 552 kJ/kg075/day in summer. J. WILDL. MANAGE. 49(2):388-393 Nutritional carrying capacity is the number of healthy individuals that can be maintained on a given habitat unit for a given time. Numerous factors collectively determine the nutritional carrying capacity of a given range, but the basic variables are the quantity and quality of forage and the species' nutrient requirements. Moen (1973), Robbins (1973), and Mautz (1978) have elaborated on the concept of nutritional carrying capacity and agree that knowledge of seasonal energy requirements is essential for determining estimates of carrying capacity. Energy requirements for several ungulates have been estimated using measurements of metabolic rate or HP (Thompson et al. 1973, Kleiber 1975) or by correlating energy intake with changes in body weight (Ullrey et al. 1970, Baker et al. 1979). White-tailed deer (Odocoileis virginianus) clearly demonstrate an annual pattern of energy expenditure, with high metabolic rates in 'Present address: Alaska Department of Fish and Game, 1300 College Road, Fairbanks, AK 99701. This content downloaded from 207.46.13.169 on Sat, 01 Oct 2016 05:18:20 UTC All use subject to http://about.jstor.org/terms J. Wildl. Manage. 49(2):1985 METABOLISM OF MOOSE * Regelin et al. 389 spring and summer and reduced rates in winter (Silver et al. 1969, Holter et al. 1977). Weiner (1977) found a similar pattern in roe deer (Capreolus capreolus), and this pattern appears to occur for most other North American cervids. Although many of these measurements were confounded by animal activity, or use of subadult animals, it is accepted that northern cervids exhibit an annual pattern of energy metabolism with a nadir in late winter. The purposes of this study were to: (1) measure metabolic rates of moose, the largest cervid; (2) determine if moose metabolic rate follows an annual pattern; and (3) obtain baseline data for a larger study to estimate the carrying capacity of moose on the Kenai Peninsula, Alaska. This paper is a contribution from Alaska Fed. Aid in Wildl. Restoration Proj. W-22-R and the Denver Wildl. Res. Cent. We acknowledge the assistance of D. C. Johnson and M. M. Schwartz in caring for the moose, H. H. Hayes for assistance with construction and operation of the metabolic chamber, and R. D. Cameron for editing the manuscript.