The use of wild and domestic animals in circus performances has declined dramatically as welfare concerns have driven legislative bans in many countries.
Circus animal welfare problems are structural. No matter how well-intentioned individual trainers may be, the fundamental requirement of continuous transport, temporary housing, and performance under loud and novel stimuli is incompatible with the welfare needs of wild animals. Elephants, big cats, bears, and primates in circuses show elevated cortisol levels, stereotypic movements, and behavioral abnormalities. The shift toward animal-free circuses using human acrobatics and technology has shown these entertainments can thrive without animal welfare compromises.