Social Play in the American Black Bear: Its Similarity to Canid Social Play and an Examination of its Identifying Characteristics

Bears evolved from a canid stock at quite a recent date (earlyMiocene). Despite this recent origin, bcars show substantialmorphological, physiologicai, and ecological differences whencompared to modern day canids. However, the display behaviorsof Canidae and Ursidae have remained remarkably similar. Inthis paper, the motor patterns of black bear social play aredescribed in detail. Numerous similarities between canid andursid social play are pointed out. Agonistic displays commonto both families are also pointed out. These behavioral similaritiessupport the principle that social behavior, particularly displaybehavior, will frequently be conservative in its evolution ascompared to the evolution of morphology, anatomy, or ecologicaladaptations. Beach (1945) stressed the importance of identifying and testingthe general characteristics of play. A large number of characteristicshave been suggested as being diagnostic of play, but these characteristicshave received very little testing. Five characteristics of socialplay were tested in this study, and two were found to be onlypartially valid for black bear social play. Extensive testingof the general characteristics of play on as wide a range ofspecies as possible is definitely recommended for future research.