Restricted feeding and circadian activity rhythms of a predatory marsupial, Dasyuroides byrnei

There is considerable disagreement as to whether food availability entrains circadian activity rhythms in omnivorous laboratory rodents. However, in carnivorous mammals a restricted feeding regime could act as a zeitgeber because the predator should hold a periodism correlated to that of the prey. Nevertheless, a restricted feeding schedule does not dominate the LD cycle for entrainment of circadian activity rhythms of the nocturnal predator Dasyuroides byrnei, nor does it entrain the free-running activity rhythms in DD. Anticipatory wheel running prior to food availability was observed in most animals. Some evidence for weak coupling between LD-entrained and meal-associated oscillators was indicated by occurrences of relative coordination. This species does not appear to have a dominance hierarchy of zeitgebern different to that reported for laboratory rodents. One would have predicted that it would have been ecologically adaptive for cycles of food availability to be more important than the LD cycle in this species.