Body water relations in two species of gerbil (Tatera indica indica and Meriones hurrianae) of the Indian desert.

The relative body water conservation efficiency of two Indian desert gerbil species, Meriones hurrianae (diurnal/crepuscular) and Tatera indica (nocturnal), has been examined under near-natural conditions in different seasons. A mean urine osmolarity of 3180 mosmol/l (maximum 4645 mosmol/l) in M. hurrianae and a mean value of 5128 mosmol/l (maximum 7547 mosmol/l) in T. indica have been recorded during summer. Urine osmolarity and urea levels indicated that while M. hurrianae remain sufficiently hydrated mainly by virtue of their feeding habit, Tatera indica may depend on the relatively higher concentrating capacity of their kidneys.