MICROHABITAT USE BY A SMALL DIURNAL RODENT (OCTODON-DEGUS) IN A SEMIARID ENVIRONMENT - THERMOREGULATORY CONSTRAINTS OR PREDATION RISK

We examined the ways a small diurnal rodent, Octodon degus, copes with high environmental temperatures in a semiarid region in northcentral Chile. We hypothesized that degus are constrained in use of microhabit at by their limited tolerance to high environmental temperatures as we ll as by presence of predators. We recorded their activity from tracks on smoked tiles, under shrubs and in the open, and in large plots wit h predators either present or excluded. We monitored body temperature in the two microhabitats during warm and cool seasons. Our results sup port our hypothesis; degus chase covered areas even when predators wer e absent. We conclude that thermal restriction is a factor in determin ing use of space by degus.