Play Partner Preferences in Siberian Ibex,Capra ibex sibirica

A study of social play in Siberian ibex kids at the Chicago Zoological Park revealed clear play partner preferences. Male kids played much more among themselves than with female kids and elicited more withdrawals by play partners than did ♀♀. ♂♂ and ♀♀ in mixed-sex bouts, played mostly with similarly aged partners. Male kids played a substantial amount with female yearlings; female kids did not. These differences support a motor training explanation of social play because they suggest that young ♂♂ in this sexually selected species discriminate in favor of partners with whom they can play forcefully.