Adults Play but Not Like Their Young: The Frequency and Types of Play by Belugas (Delphinapterus leucas) in Human Care

摘要

While play occurs in many taxa with yo unger conspecifics engaging in play behaviors more often than older conspecifics, little empirical research currently exists on play by white whales, or belugas, ( Delphinapterus leucas). The purpose of the current study was to explore the types of play exhibited by a group of belugas in human care. Archived video footage representing 24.5 hours of observation time collected over three years for 14 belugas (5 immature and 9 adults) was coded for type, frequency, and duration of all play events. Out of 2,092 play events, the belugas produced 497 bouts of play and preferred to engage in independent forms of play (92%) as opposed to coordinating their activities together (8%). Immature belugas exhibited four times as many play bouts (n = 405) compared to adult play events (n = 92) and included motor play, water play, and object play as well as some social interactions (e.g., play chases). When compared to all types of play, play with objects represented 50% of the bouts, and when the degree of diversity of play was considered all belugas showed more diversity with environmental enrichment devices (EEDs) present (83% of diverse play bouts) than when exhibiting motor or water play. Age and sex of the belugas also influenced the type of play (i.e., motor, water, or EEDs) exhibited during different degrees of complexity of play bouts (i.e., single events, repetitive bouts, diverse bouts, and complex cooperative social play) . When sex of the beluga was considered, males appeared to prefer to engage in mot or play while females appeared to prefer to engage in object play during single play events (males: n = 68, 64%, females: n = 55, 52%) and repetitive bouts (males: n = 18, 62%, females: n = 20, 54%). Some comp lex cooperative play bouts between immature bel ugas and between immature and adult belugas (n = 42, 10%) were observed. Play bouts involving EED s lasted significantly longer (M = 55.38 sec, s = 2.85) and produced greater diversity in play behaviors for all belugas combined. In summary, belugas of all ages engage in spontaneous play behaviors, but the age and sex of each beluga produce different play preferences.