Sex Differences in the Play Behavior of Yearling Yellow‐bellied Marmots

Abstract
Play in yearling yellow‐bellied marmots (Marmota flaviventris) was studied under non‐manipulative field conditions in the Upper East River Valley of Colorado. The behavior patterns constituting play were described and illustrated and 12 specific hypotheses related to sex differences were tested. The results of these tests were used to evaluate the adaptive significance of play by comparing two major functional hypotheses: motor training and social cohesion.