Modern zoos vary enormously in quality, from exemplary conservation institutions to operations that cause significant animal suffering through inadequate space and enrichment.
Well-managed, accredited zoos provide strong veterinary care, enriched habitats, social groups and conservation programmes that justify their existence. However, many zoos — particularly in low-income countries and in roadside attractions — provide barren environments that cause chronic psychological harm. Species particularly poorly served by captivity include polar bears, elephants and big cats with large home range requirements.