Energetic benefits provided by sharing a nest were investigated by measuring resting metabolic rate in the lesser mouse lemur (Microcebus murinus), a nocturnal solitary primate that usually groups in a nest during its diurnal rest. Resting metabolic rate was measured on 32 individuals maintained either alone or grouped with one, two, or three conspecifics originating from the same social group. In this seasonal breeder, individual resting metabolic rate varied significantly from 1.08 ± 0.03 to 1.47 ± 0.05 (SE) ml O2 h™1g™1 for nonbreeding and breeding seasons, respectively. During the breeding season, both sexes reduced their energetic expenditure by 20% when grouped in pairs, and maximal energetic benefit (40%) was achieved when three animals nested together. During the nonbreeding season, maximal energetic gain was observed when as few as two animals nested together because resting metabolic rate was already decreased. Finally, when three or four animals shared the same nest, resting metabolic rate was minimal, independent of sex and season, at 0.88 ml O2 h™1g™1, suggesting that nest-sharing in this solitary primate is an important strategy to minimize energetic costs to cope with seasonal shortage of food.

Author notes

Associate Editor was Allen Kurta.