Young Belugas Diversify Adult Beluga (Delphinapterus leucas) Behavior

摘要

Across the animal kingdom, immature animals are characterized by their playfulness and diversity of behavior, but are their actions enriching to adult conspecifics. The purpose of th is stud y was to assess if beluga (Delphinapterus leucas) calves influenced the behavioral repertoire of adult conspecifics, specifically with regard to play behaviors, social interactions, and solitary swimming. Video recordings made between 2012 and 2015 (200+ hrs) were rando mly selected using the following social groupings: adults only ( n = 13), adults with juvenile (n = 28), mother-calf pairs (n = 24), mother-calf pairs with juvenile (n = 26), and mixed groups (n = 84) that included different ages and sexes. Each recording was coded using a 1-min instantaneous sampling method for 7 behavioral categories that were grouped into 4 major categories: mother-calf swim, social interactions, play, and solitary swims. Results indicated that the social grouping influenced the behavioral categories even when number of animals in the social grouping was controlled. Adults displayed solitary swims significantly (p 0.001) more often when grouped with each other (adjusted M = 86%) or with juvenile belugas (adjusted M = 85%) than any other combination in which calves were present (adjusted M ranged between 42% – 64%). The presence of calves also significantly (p = 0.002) increased the number of play activities observed for adults (Adults only: adjusted M 0%; Mixed: adjusted M = 11%). The percent of social interactions did not significantly (p = 0.196) change across the different social groupings. The results demonstrate that the presence of beluga calves decreased the percent of time adults spent in solitary swims and increased the percent of time adults spent in other activities, including play behaviors and social interactions. The presence of beluga calves is associated with increased diversity of the behavioral repertoires of adult conspecifics.