The complexity of enclosure design is as important as size for zoo carnivore welfare, with habitat heterogeneity enabling behavioral diversity that size alone cannot provide.
Enclosure design for zoo carnivores has evolved from size-focused thinking toward complexity-focused design. Research has demonstrated that the heterogeneity of the environment - the variety of substrates, elevations, hiding spots, water features, and vegetation - predicts behavioral diversity better than simple area measurements. A large, featureless enclosure provides less welfare benefit than a smaller, complex one. This insight redirects zoo investment from maximizing footprint to maximizing habitat complexity within available space, enabling more effective welfare improvement within existing facilities.