Environmental enrichment in zoos aims to improve animal welfare by enabling natural behaviors. The science of enrichment has advanced substantially, revealing what genuinely improves welfare versus what merely occupies animals.
Zoo enrichment has evolved from well-intentioned but superficial interventions toward evidence-based programs grounded in behavioral ecology. Simply providing novel objects does not constitute good enrichment if animals habituate quickly or the enrichment doesn't engage natural behavioral systems. A polar bear given a rubber ball may interact with it briefly but remains deprived of the hunting, swimming, and exploring that drive its motivation systems. Effective enrichment engages the specific behavioral systems that matter for each species - foraging complexity for primates, swimming opportunities for polar bears, scent trails for carnivores. The welfare science of enrichment is now sophisticated enough to evaluate programs rigorously rather than accepting that any enrichment is better than none.