The use of wild animals in circuses causes significant welfare harm through training methods, confinement, and travel.
Circus animal training exploits the same pain-avoidance mechanisms that cause animals to avoid threats. Getting tigers to sit on pedestals or elephants to stand on two legs requires overcoming powerful behavioral resistances, typically through punishment and food restriction. The traveling lifestyle means months in transport, brief performances, then more confinement. The suffering is systematic rather than incidental.