Behavioral Ontogeny Analysis of Sciurid, Rodents, with Emphasis on the Social of Ground Squirrels [Analyse ontogénétique du comportement des Sciuridae, Rongeurs, particulièrement du comportement social des écureuils terrestres].

Résumé

The purposes of this chapter are to suggest a standardized method for data collection with regard to behavioral ontogeny, to promote interspecilic comparisons as essential tools for understanding the adaptive "fine tuning" of developmental patterns, and to synthesize current knowledge of the ontogeny of social behavior in ground squirrels. Behavioral development can be divided into two parts: emergence of behavior patterns during early ontogeny, and integration to adult life during later ontogeny. Observations during early ontogeny are compiled in the following manner: for each behavior pattern, the earliest and latest ages of appearance of the behavior are given with a mean calculated for a series of young of each species. An analysis of the ontogeny of social behavior of two ground squirrels, Spermophilus columbianus and Spemophilus lateralis, is performed in this manner. The results are then compared with those obtained for two arboreal squirrels Tamiasciurus hudsonicus and Glaucomys sabrinus. From this comparison and other data available on ground squirrels, it appears that gross interspecific differences in ontogenetic rates are controlled by factors such as predation pressure, hibernation, and complexity of locomotion. Interspecific differences in the development of agonistic, cohesive, and neutral behavior patterns in grounds squirrels are probably linked to social organization within each species. Data collection during later ontogeny should be concerned with the following parameters social interactions with the different categories of kin and nonkin, dispersal, variation in home range, behavioral time budget, and activity cycles of juveniles. Some results concerning ground squirrels are presented, and their relation to adult social organization is discussed. Recommendations on the orientation of further studies on behavioral ontogeny in ground squirrels complete this review.