US-IALE 2018

AUTHORS: Roger A. Powell, North Carolina State University; Aaron N. Facka, Oregon State University; Lynn L. Rogers, Wildlife Research Institute; Susan A. Mansfield, Wildlife Research Institute

ABSTRACT: Most researchers estimate home ranges using telemetry location estimates. With an appropriate estimator, this approach produces a utilization distribution that can be considered to approximate a probability distribution of where an animal spends its time. Essentially all home ranges estimated today use time as their currency. Estimating home ranges using other currencies, such as energy expenditure and importance of resources, provides insights into why animals use space as they do. Weighting each telemetry location by rate of energy expenditure at that time, estimated from travel speed using an equation in the literature, produces a new utilization distribution. For some animals, energy expenditure in their home range cores is higher, and in the home range peripheries lower, than time spent in those areas. Home range estimators have parameters that must be chosen to be appropriate to the biology of study animals and research technology. Choosing those parameters based on perceptual distances for sight, sound, smell and memory produce different utilization distribution yet, explaining different aspects of why animals use space as they do. I present data for fishers (Pekania pennanti) and black bears (Ursus americanus) to illustrate and to compare how using different currencies and perceptual distances affect utilization distributions, home range overlap, and home range cores. Techniques appropriate to the questions or specific hypotheses are needed to understand animal behavior and the potential for successful management.