Play activities of the black-tailed deer in northwestern Oregon

Play behavior of black-tailed deer (Odocoileus hemionus columbianus) was observed on 42 different occasions on the Cedar Creek area of northwestern Oregon.Play patterns were categorized as (1) contagious, (2) exploratory, (3) care-soliciting, (4) sexual, and (5) agonistic.A total of 23 deer exhibited contagious play patterns during eight events.Seven male fawns performed 'exploratory play patterns on seven occasions.Two female and two male fawns exhibited care-soliciting play patterns on four occasions.Sexual play in the form of playful mounting was observed on 13 occasions.Ten deer exhibited agonistic play patterns on 10 occasions.The dominance hierarchy seemed to break down completely during play.Sexual play among fawns was without regard to sex, whereas yearlings and older deer of only the same sex were observed in sexual play.