title: Torpor use during gestation and lactation in a primate.
abstract: Torpor is an energy-saving mechanism that allows endotherms to overcome energetic challenges. Torpor should be avoided during reproduction because of potential incompatibility with offspring growth. To test if torpor can be used during gestation and lactation to compensate for food shortage, we exposed reproductive female grey mouse lemurs (Microcebus murinus), a heterothermic primate, to different levels of food availability. Torpor use was characterised by daily skin temperature profiles, and its energetic outcome was assessed from changes in body mass. Food shortage triggered torpor during the end of the gestation period (n = 1), ranging from shallow in response to 40% food restriction to deep daily torpor in response to 80% restriction. During the early period of lactation, females fed ad libitum (n = 2) or exposed to a 40% restriction (n = 4) remained normothermic; but 80% food restricted females (n = 5) gave priority to energy saving, increasing the frequency and depth of torpor bouts. The use of torpor was insufficient to compensate for 80% energetic shortage during lactation resulting in loss of mass from the mother and delayed growth in the pups. This study provides the first evidence that a heterothermic primate can use torpor to compensate for food shortages even during reproduction. This physiological flexibility likely evolved as a response to climate-driven fluctuations in food availability in Madagascar.
authors.affiliation: UMR 7179 CNRS-MNHN, Département Ecologie et Gestion de la Biodiversité, Muséum National d'Histoire Naturelle, 1 avenue du Petit Château, 91800, Brunoy, France. canale.c.i@gmail.com
authors.forename: Cindy I
authors.initials: CI
authors.lastname: Canale
authors.forename: Martine
authors.initials: M
authors.lastname: Perret
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Henry
mesh_terms: D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000502:physiology*; D031204:Caloric Restriction; D016565:Cheirogaleidae / Q000378:metabolism / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000502:physiology*; D011247:Pregnancy; D012098:Reproduction / Q000502:physiology; D015431:Weight Loss / Q000502:physiology