Environmental enrichment: increasing the biological relevance of captive environments

Newberry argued that effective enrichment is not about adding novelty for its own sake but about increasing the biological relevance of captive environments, that is, providing opportunities for animals to perform behaviours important in their natural lives. She proposed evaluating enrichment by whether it improves biological functioning and welfare, not merely whether animals interact with it. The paper provided a rigorous conceptual definition that helped distinguish meaningful enrichment from superficial change, and it stressed measuring outcomes such as health, reproduction and behavioural normality. Widely cited across taxa, it shaped how felid and carnivore enrichment programs justify and assess their interventions, emphasising function over form.