Circadian rhythms of wheel-running in the Eastern Quoll, Dasyurus viverrinus (Marsupialia: Dasyuridae).

Abstract

In experiment I the circadian rhythms of wheel-running of ten Dasyurus viverrinus were examined after 34 days under a 14:10 h light/dark cycle. Nine animals exhibited a nocturnal pattern of wheel-running. They commenced wheel-running just after lights off and continued to run for up to 8 h before a period of relative quiescence ensued 2- 4 h prior to lights on. A single animal exhibited a more labile pattern of entrainment to the light/dark cycle with activity distributed over both the light and dark periods. In experiment 2 the free-running period of the wheel-running rhythm was measured during 23 days in constant darkness and again during 20 days in constant light (10 lux). In constant darkness the animals' mean free-running period was 24.22 h, while in constant light the mean free-running period was significantly longer (24.41 h). It appears that the circadian system of D. viverrinus functions in a manner similar to that of the nocturnal rodents.