From welfare indicator to welfare contributor: the role of play in building flexibility and resilience in captive animals.

Multiple behavioural indicators have been explored to understand how captive individuals feel about certain environments and events, one of which is play. However, play likely also contributes to enhancing future welfare. A key pathway linking play and welfare may lie in the development of flexibility and resilience, which enable individuals to adapt and manage the inevitable challenges they will experience. This article develops a framework for how play contributes to captive animal welfare through flexibility and resilience by synthesizing theories from multiple fields, including the training for the unexpected theory, the broaden-and-build theory of positive emotions and the cognitive bias literature. Findings from multidisciplinary studies, including those assessing the correlates of the playfulness trait in humans, the effect of play interventions on flexibility in children and the impact of social play deprivation in rodents, provide preliminary support for these play-flexibility-resilience relationships. We provide recommendations for future approaches to the play-welfare relationship in captive animals, including exploring how play can be used to enhance long-term welfare, the welfare impact of play in adult versus young animals and the differences between play types, and whether and how the playfulness trait contributes to welfare across species.