The Ontogeny of Social Behavior of Uinta Ground Squirrels

The social behavior of juvenile Uinta ground squirrels (Spermophilus armatus) was studied for 2 1/2 years in northeastern Utah. The purpose of the study was to describe the developing social behavior of unconfined, marked squirrels. Their behavior was recorded with motion pictures and written descriptions from the time they emerged from the natal burrow until they entered hibernation. Three phases of behavioral development were apparent. The first phase began when the juveniles appeared above ground and ended 5 weeks later. This was a period of socialization and consisted of behavioral patterns best described as play. The second phase began abruptly with the development of intolerance and attachment to a particular site. The agonistic behavior of juveniles at this time was much the same as the adult pattern. The third phase began when they had been above ground about 8 1/2 weeks and ended with hibernation, at about 11 weeks. During this period juveniles combined the behavioral patterns of the first two periods . However, they became progressively less active as hibernation approached. Sex was an important determinant of the developing behavior of juveniles. Although males and females had similar behavioral repertoires, the frequency with which they performed specific activities often differed between the three periods