Environmental enrichment for zoo animals has advanced from ad-hoc novelty provision to a science-based practice aimed at promoting species-appropriate behavioral expression.
Zoo enrichment science has matured significantly from early notions of simply providing 'things to do.' Effective enrichment is grounded in understanding species-specific behavioral needs, motivation, and cognitive capacity. Enrichment that provides choice, controllability, and unpredictability activates positive welfare states more reliably than passive novelty. For cognitively complex species including great apes, cetaceans, and elephants, the quality and variety of enrichment must match their sophisticated behavioral needs or welfare gains are limited. The science increasingly recognizes that the best enrichment provides animals with agency over their environment - the ability to make meaningful choices.