Adaptative modifications of behavior in mammals of the Eurasian steppes [Modifications adaptatives du comportement chez les mammifères].

Résumé

The vast steppe zone of Eurasia is inhabited by about 90 species of mammals, and one-thrid of them are steppe endemics. Herbivores obtain food from the many species of nutrient-rich grasses and herbs in the diverse steppe vegetational associations. Many small rodents and lagomorphs have elaborate behavioural patterns associated with storage of dry plant parts for winter. Burrowing adaptation are also important in providing cover from predators and suitable microclimates in the steppes, which are much more exposed to direct climatic influences than forest biotopes. Related to burrowing are daily and seasonal patterns of activity, and the abundance of hibernating species in the steppe fauna. Steppe mammals are grouped by life forms, based on trophic relationships, ecological stratum occupied, social behavior, seasonal activity patterns,etc. The behavioral adaptations of four such life forms os steppe mammals are discussed in detail.