Article du Bulletin
Bilancio energetico nella Marmotta alpina durante l'iibernazione e in condizioni di normotermia. Energetics of normothermic and hibernatting alpine marmots [Bilan énergétique de la marmotte alpine au cours de l’hibernation et en normothermie].
Ortmann S. & Heldmaier G. · 1992 · Proc. 1st International Symposium on Alpine Marmot (Marmota marmota) and on Genus Marmota, Bassano et al. eds., 221-225.
Résumé
During hibernation marmots lower their body temperature in order to avoid the higher energy requirement which are necessary for maintaining normothermia. Metabolic heat production decreases to approximately 5% of the normothermic basal value in winter at thermoneutrality. Due to the fact that body temperature of hibernating mammals is controlled by thermoregulation, metabolic heat production rises linearly if ambient temperature decreases below 5 C while Tb remains constant. Besides the reduction of metabolic rate during hypothermia Alpine marmots exhibit an annual cycles of basal metabolic rate with a maximum of 285 mlO2 (Kg/h) in winter. This seasonal reduction of resting metabolic rate reduces energetic costs and support fattening in fail.