Social context shapes play behavior in wild Asian elephant calves
摘要
Play is an important component of locomotor, neural, and social development in mammals, yet factors structuring play expression in wild Asian elephant (Elephas maximus) calves remain poorly understood. We conducted focal observations of 34 individually identified calves in Minneriya and Kaudulla National Parks, Sri Lanka to characterize play repertoires and test predictions about developmental, social, and anthropogenic influences. Calves exhibited locomotor play, social play, object play, and object play with conspecifics. Locomotor and social play occurred most frequently (6.62 and 5.87 events/hr), while object-oriented play was rare. Activity budgets differed by age: year-olds allocated more time to foraging (33.8% vs. 6.8%), while newborns spent more time manipulating objects (26.7% vs. 9.4%). Contrary to predictions, age did not predict play occurrence (P = 0.912) or play rate (P = 0.737). Spatial independence from adult females, however, was a significant predictor: calves ≥ 1 m from the nearest female exhibited 44% higher play rates (P = 0.034) and 81% lower odds of adult-directed interactions (P = 0.007), consistent with peer-oriented sociality during spatial autonomy. Tourism pressure did not predict rates of play (P = 0.409 and P = 0.458). High session-level variability (25% of sessions contained no play) indicated facultative expression in response to immediate context. These findings demonstrate that early-life play in wild Asian elephants can be shaped more strongly by fine-scale social positioning than by chronological age or measured anthropogenic disturbance, with implications for assessing calf welfare in wild and captive populations.