Meeting Abstract

P1.8  Tuesday, Jan. 4  Biophysical modeling of the temporal niche: From first principles to the evolution of activity patterns LEVY, O; DAYAN, T; KRONFELD-SCHOR, N*; PORTER, WP; Tel-Aviv University, Tel-Aviv; Tel-Aviv University, Tel-Aviv; Tel-Aviv University, Tel-Aviv; University of Wisconsin, Madison NogaKS@tauex.tau.ac.il

Most mammals can be characterized as nocturnal or diurnal. However infrequently, species may overcome evolutionary constraints and alter their activity patterns. We modeled the fundamental temporal niche of a diurnal desert rodent, the golden spiny mouse, Acomys russatus, and compared metabolic costs of diurnal vs. nocturnal activity using a biophysical model. The model predicted that energy expenditure during foraging is almost always lower during the day except during mid-day in summer at the less sheltered microhabitat. Previous work suggested that A. russatus shifted to diurnality in response to competition by their nocturnal congener, A. cahirinus; adaptation to diurnality may reflect the ‘ghost of competition past’, or may suggest climate-driven diurnality as an alternative hypothesis. While climate is considered to play a major role in the physiology and evolution of mammals, this is the first study to model its effect on the evolution of activity patterns of mammals.