Seasonal activity in the blind mole rat (Spalax ehrenbergi)

Mole rats had a diurnal monophasic locomtor activity pattern with activity peaks from 08:00-13:00 and from 11:00-19:00 during summer and winter, respectively. Activity periods were punctuated by several rest breaks, and, conversely, rest periods were interrupted by short spells of activity. Duration of activity was 6.6±0.4 h (mean±SD) in summer and 7.9±2.3 h in winter. In the laboratory, mole rats entrained activity, under constant dim light, to a single daily 20-s light pulse. Brief light pulses perceived through the mole rats' rudimentary eyes while they are pushing excess soil out of the tunnel to the ground surface, are probably the main Zeitgeber that entrains their locomotor activity to the diurnal pattern. Air and soil temperatures are the secondary cues that finely tune the activity to the morning during summer and the late afternoon during winter. -from Authors