Modern zoo accreditation increasingly requires evidence of animal welfare alongside conservation contribution, but standards and enforcement vary widely.
Zoo animals experience significant welfare variation by species, facility quality, and management. Great apes and elephants are particularly challenging to keep to high standards. Repetitive stereotypic behaviour remains common in large predators and elephants. Conservation justification alone does not offset welfare harms. The best modern zoos create naturalistic, enriched environments and contribute substantially to field conservation. The worst perpetuate suffering with minimal benefit.