Variable Energy Demands in Pseudomys hermannsburgensis: Possible Ecological Consequences

Abstract

The energy metabolism of Pseudomys hermannsburgensis, a native Australian desert rodent, was investigated with animals captured in the field. Animals showed large variation in basal metabolic rate between two time periods [November 1991 (1·40 ± 0·38 mL 0 ₂ g^-1 h^-1 ) and September 1992 (3·58 ± 0·24)], producing values that generally differed from those predicted from body mass. P. hermannsburgensis also entered torpor, which has not been demonstrated previously in an Australian rodent. Environmental stimuli for changes in metabolic rates are not clear. Possible ecological advantages of the observed patterns of energy metabolism are conservation of energy and water and increased longevity. All three factors may be considered adaptations to the variable desert environment.