Development of Sociality and Emergence of Independence in a Killer Whale (Orcinus orca) Calf From Birth to 36 Months

Dolphin calves spend most of their time swimming with their mother immediately after birth. As they mature, the calves become increasingly independent, and begin to interact more often with other calves, juveniles, and sub-adults. For bottlenose dolphin calves, sociality is related to maternal behaviors. Unfortunately, much less is known about the development of sociality and emergence of independence for killer whale calves. The purpose of this study was to examine the developmental changes in social behaviors and solitary activities of a killer whale calf across a 36-month period. Focal follow video recordings of a mother-calf pair housed at SeaWorld San Antonio were collected 2-6 times a day for 5-15 min at 6-month intervals. Using a sample of randomly selected video recordings at each month, developmental changes in swims and social interactions with her mother, swims and social interactions with non-maternal partners, and solitary activities (e. g., solitary swims, solitary play) were observed across the months. The calf spent most of her time swimming with the mother across the 36-month period. The time the calf socialized with her mother was greater than the time she socialized with others at each month. Besides her mother, the calf socialized more often with the other adult female compared to adult males. As the calf matured, the increase in the time she spent socializing with adult killer whales other than the mother corresponded with an increase in the rate and time spent in solitary play. The developmental trends of sociality and emerging independence replicate research conducted with calves of other dolphin species. (C) 2016 Wiley Periodicals, Inc.