Animals communicate their welfare state through behavior. Learning to read behavioral signals enables better assessment of welfare and earlier identification of welfare problems.
Behavioral welfare indicators provide real-time information about animal experience that physiological measures cannot. Play behavior — especially social play — is one of the most reliable positive welfare indicators, occurring only when animals are free from significant stress, fear, pain, or hunger. Stereotypic behaviors indicate chronic welfare deficits: they develop when animals are consistently prevented from performing highly motivated behaviors and become fixed despite the original motivation disappearing. Fear indicators including avoidance of humans, freezing, and immobility in the presence of novel stimuli indicate negative experience that often traces to inadequate socialization or aversive handling. Training stockpersons, veterinarians, and researchers to accurately read these indicators and respond to welfare-relevant signals would improve outcomes across all human-animal contexts.