Back to Publications Zurück zu den Veröffentlichungen J. Zool., Lond. (2004) 262, 281–288 ©2004 The Zoological Society of London Printed in the United Kingdom DOI:10.1017/S0952836903004643
Body temperature and above-ground patterns during hibernation
in European hamsters (Cricetus cricetus L.)
Thomas Wassmer*
Department of Biology, University of Konstanz, P.O. Box 5560 M618, D-78434 Konstanz, Germany
(Accepted 3 September 2003)
Abstract
The purpose of this study was to determine whether hibernating European hamsters Cricetus cricetus, L., 1758
stay in their burrows all winter or if they occasionally spent time above ground. If ‘time (spent) above ground’
(TAG) occurred regularly throughout hibernation, the second objective of this work was to categorize and quantify
the patterns of TAG during winter. For this purpose, 11 European hamsters were individually housed in wire mesh
cages that were buried in the ground of an outdoor enclosure. Each cage was filled with soil up to ground level
allowing the animals to construct their own burrows within the cages. Antennae in the bottom and top of the cage
were calibrated to receive signals only when the hamsters were in their burrows or above the ground, respectively.
This method enabled continuous recordings of the animal’s TAG and provided ecologically meaningful results as
the animals were housed in a way that closely resembled their natural habitat. About half of the hamsters stayed
continuously below ground. Of these hamsters, almost all showed a dense pattern of episodes of reduced body
temperature separated by only brief periods of normothermia. In contrast, the other half of the animals moved
either episodically or even regularly above ground. For all of these hamsters, TAG was significantly reduced as
compared to normothermic values. One hamster did not show any hibernation but did have a significantly reduced
normothermic body temperature and did not leave its burrow for periods of up to 3 weeks.
Key words: Cricetus cricetus, hibernation, burrow, temperature, thermo-sensitive transmitter, time spent above
ground