title: Basal blood glucose concentration in free-living striped mice is influenced by food availability, ambient temperature and social tactic.
abstract: Vertebrates obtain most of their energy through food, which they store mainly as body fat or glycogen, with glucose being the main energy source circulating in the blood. Basal blood glucose concentration (bBGC) is expected to remain in a narrow homeostatic range. We studied the extent to which bBGC in free-living African striped mice (Rhabdomys pumilio) is influenced by ecological factors with a bearing on energy regulation, i.e. food availability, abiotic environmental variation and social tactic. Striped mice typically form extended family groups that huddle together at night, reducing energetic costs of thermoregulation, but solitary individuals also occur in the population. We analysed 2827 blood samples from 1008 individuals of seven different social categories that experienced considerable variation in food supply and abiotic condition. Blood samples were taken from mice in the morning after the overnight fast and before foraging. bBGC increased significantly with food plant abundance and decreased significantly with minimum daily ambient temperature. Solitary striped mice had significantly higher bBGC than group-living striped mice. Our results suggest that adaptive responses of bBGC occur and we found large natural variation, indicating that bBGC spans a far greater homeostatic range than previously thought.
authors.affiliation: University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland carsten.schradin@iphc.cnrs.fr.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schradin
authors.affiliation: School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Neville
authors.initials: N
authors.lastname: Pillay
authors.affiliation: University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Kondratyeva
authors.affiliation: School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Chi-Hang
authors.initials: CH
authors.lastname: Yuen
authors.affiliation: School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
authors.forename: Ivana
authors.initials: I
authors.lastname: Schoepf
authors.affiliation: XBehavior GmbH, Bänk Dägerlen, Switzerland.
authors.forename: Sven
authors.initials: S
authors.lastname: Krackow
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D004777:Environment; D005247:Feeding Behavior; D051189:Murinae / Q000502:physiology*; D012919:Social Behavior; D013019:South Africa; D013696:Temperature
chemical_list: D001786:Blood Glucose
keywords: allostasis; homeostasis; phenotypic flexibility; physiological adaptation