In reptiles, habitat selection is the process whereby suitable habitat is selected that optimizes physiological functions and behavioral performance. Here, we used the brown forest skink ( Sphenomorphus indicus
) as a model animal and examined whether the frequency of active individuals, environmental temperature, illumination of activity area, and habitat type vary with different age classes. We surveyed the number of active individuals and measured environmental variables at Baiyunshan Mountain in Lishui, Zhejiang, China. We found no difference in the activity frequency of adult and juvenile S. indicus
; the activity pattern of active individuals was bimodal. The mean environmental temperature selected by adults was higher than that selected by juveniles. The environmental temperature of active areas measured at 0900-1000 h and 1100-1200h was higher than at 1400-1500h; illumination of the active area at 1000-1200h was also higher than at 1400h-1600 h. The number of active individuals, the environmental temperature and illumination of activity areas showed pairwise positive correlation. There was a difference in habitat type between juveniles and adults whereby juveniles prefer rock habitats. We predict that active S. indicus
select optimal habitats with different environmental temperatures and types to reach the physiological needs particular to their age classes.