Understanding the behavioural needs of zoo animals requires knowledge of their wild ecology and evolutionary history. Matching exhibit design to behavioural needs is the foundation of modern zoo welfare science.
Zoo animal welfare is determined by the match between an animal's evolved behavioural needs and the opportunities provided by its captive environment. When this match is poor, animals develop stereotypies and show indicators of chronic stress; when the match is good, animals exhibit species-typical behaviour, normal physiological parameters, and positive affective states. The science of behavioural needs provides the evidence base for exhibit design, enrichment programmes, and husbandry practices. Translating this science into consistent practice across the diversity of zoo species remains challenging — the welfare literature is extensive for charismatic megafauna but thin for many reptiles, birds, and invertebrates. Expanding welfare research coverage and integrating findings into accreditation standards is the priority for zoo welfare science.