Terrain preferences in the play behavior of Siberian ibex kids (Capra ibex sibirica).

Play behavior was studied in a captive group of Siberian ibex at the Chicago Zoological Park. The hypothesis that physical training effects were at least partially responsible for the evolution of play in this species was tested by noting the amounts of play which occurred on flat and on sloped surfaces. The kids showed a clear preference for play on sloped terrain, even though this choice resulted in considerably greater risks. The danger involved in highly active locomotor play performed on steeply sloped areas is presumably outweighed by the physical training benefit for an adult life spent moving in precipitious areas.