Play Behavior in Two Captive Bottlenose Dolphin Calves (Tursiops truncatus): Ethogram, Ontogeny, and Individual Differences.

Abstract

This research focused on different aspects of play behavior including ethogram, ontogeny, and individual differences, in one male and one female captive bottlenose dolphin calves (Tursiops truncatus) from November 2003 to June 2004. We presented the first peer-reviewed description of a play ethogram in bottlenose dolphin calves whose behaviors were grouped into three hierarchical levels: two categories: solitary and social play; four subcategories: locomotor, object, bubble play, and in the presence of humans, and 35 entries. It was conducted in two phases: the descriptive phase - from 3 to 5 months old - with 29 entries and the quantitative phase - from 6 to 10 months old -with six entries. All social and solitary locomotor behaviors appeared when animals were 3 months old meanwhile more complex behaviors concerning playing with objects, bubbles, and in the presence of humans were observed for 6 months old. There were no statistically significant intra-individual and inter-individual differences in the play behavioral diversity, in the time invested in play and in the Shannon's evenness index. However, we observed statistically significant inter-individual but not intra-individual differences for the Shannon's diversity index.