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Résumé

The behavioural ecology of the Alpine marmot Marmota marmota, Linnaeus, 1758) has been studied in the French AIps since springtime 1990. The aim of this study is to understand the socio-spatial structure of this species and to compare it to that of North-American species from an evolutionnary and ecoIogical point of view (Armitage, 1988, Barash, 1974). Four neighbouring social units were studied during two years from June to the end of September (onset of hibernation) in the Nature Reserve of La Grande Sassière (Vanoise National Park, Savoie, France). Observations were performed by scan sampling or ad libitum to establish the ethogram. The social unit was the family, group, composed of an adult male, an adult female, and their offspring of the two previous years (Arnold 1979). The group shared a common home range, the size of which varied from 0.9 to 2.8 ha with an overlapping rate of 9 to 12.5%. The home range included a central Main Burrow System (MBS : hibernaculum, sleep and birth place) and peripheral areas with auxilliary burrows or shelters. Temporal and spatial distribution of activities were established by taking into account behavioural patterns of both individuals and social encounters. Results showed the general pattern for both spatial and temporal activitie to be under the influence of day and seasonal variation. All activities were performed on the MBS, but some of them were specific to this area. Peripheral areas were mainly used for foraging. Activity increased in August and decreased in September and was gradually concentrated in the vicinity of the MBS. Differences between groups were considerable and related at least to social factors (group structure) and spatial factors (home-range structure and size). The social structure of Marmota marmota seems to be closer to the structure of M. caligata and M. olympus, as predicted by Barash, than to the structure of M. flaviventris or M. monax.