ABSTRACT
Alpine marmots (Marmota marmota) hibernate for 6 to 7 months each year. Marmots were kept in three small family groups in outdoor enclosures which were equipped with artificial burrows at Marburg. They were trapped in the Alps (Berchtesgaden) 1 year prior to the experiments. During the summer season adult marmots were implanted with temperature transmitters. Prior to hibernation individual marmots were removed from the group and transferred to perspex boxes in climate chambers. Marmots can store a large amount of body fat which will provide them with a sufficient amount of energy for hibernation, even at their preferred moderate body temperature. The energy budget for marmots would require the consumption of 1317 g fat for the entire hibernation season, which matches their actual weight loss of 1438 g. An efficient way to save additional energy during hibernation would be a prolongation of hibernation bouts thereby reducing the duration of euthermic periods.
