Winter Activity Patterns of Moose in Interior Alaska

Abstract

Moose (Alces alces) diel activity patterns were studied in Denali National Park and Preserve (DNPP), Alaska, during the winter-spring period, 1983-84. Mean active time/24-hour day increased from 5.8 hours in early February to 7.8 hours by late April. Moose averaged 5-6 feeding periods/24 hours. Bedding periods averaged 178 minutes and feeding periods 68 minutes. Feeding and bedding periods alternated in a polyphasic pattern and were generally synchronized among individuals. Activities associated with resting and foraging constituted 99.3% of moose winter time budgets. Moose, on average, spent 66.9% of bedding periods ruminating and 76.2% of feeding periods harvesting and ingesting forage. Variations in daily activity levels were related to daily movements by moose. Distance travelled increased exponentially as the duration of foraging periods increased. Seasonal changes in levels of activity appear to reflect behavioral and physiological adaptations of moose to temporal changes in forage quality and patterns of forage distribution. J. WILDL. MANAGE. 50(4):727-734 Knowledge of daily and seasonal activity pattern's is essential for the construction of timeenergy budgets, and for evaluating foraging and survival strategies of animals in seasonal environments. When combined with estimates of the energetic costs of various activities, these data can provide estimates of daily, seasonal, and annual energy expenditure and can be integrated into bioenergetic models used to estimate range carrying capacity (e.g., Weiner 1975, Moen 1978, Swift 1983). In addition, it has been demonstrated that animal sightability during aerial surveys is strongly influenced by animal activities (Gasaway et al. 1981). Consequently, a better understanding of animal activity patterns could improve the efficiency of aerial survey methods. Recent advances in motion-sensing biotelemetry (Cederlund 1981, Garshelis et al. 1981, Georgii 1981) have made it possible to reliably estimate 24-hour activity patterns of wild, freeranging ungulates. Circadian patterns of activity have been documented in a number of northern ruminants (Craighead et al. 1973, Gates 1980, Cederlund 1981, Georgii 1981, Renecker and Hudson 1983) and appear to be the result of endogenous or physiological factors and environmental influences (Aschoff 1963). The objective of this study was to describe the diel activity patterns of wild, free-ranging moose in DNPP during the winter-spring period. This project received financial and logistical support from Michigan Tech. Univ.; the Natl. Rifle Assoc.; Eddie Bauer, Inc.; Sigma Xi; L. G. Adams; the U.S. Natl. Park Serv.; and the U.S. For. Serv. Inst. North. For. M. A. Masteller and B. W. Dale provided invaluable field assistance. V. Van Ballenberghe and R. O. Peterson provided technical and logistical advice. R. G. Weingardt provided assistance with statistical analysis. V. Van Ballenberghe, R. J. Hudson, D. G. Miquelle, R. O. Peterson, and L. A. Renecker provided useful comments on early drafts of the manuscript.