Advancing evidence-informed practice in modern zoos: research priorities for animal welfare, conservation, and social legitimacy.

Modern zoos operate at the intersection of conservation responsibility, ethical accountability and scientific advancement, while facing increasing public scrutiny and rising expectations for transparency and measurable impact. This scrutiny often focuses on animal welfare and the justification for maintaining wild animals in captive environments. Consequently, there is a growing need for zoo-based research to move beyond often anecdotal practice toward robust, evidence-informed decision-making. Evidence refers to systematically collected data and critically evaluated research used to inform management strategies that promote the zoo's key aims. This article synthesises key areas in which contemporary zoo operations rely on limited or untested evidence and identifies priority research questions critical to the future legitimacy and effectiveness of zoos. The paper explores several interlinked themes: the welfare implications of reproduction and breeding management; the role of social bonds in welfare, stress resilience, and translocation outcomes; the underrepresentation of nutrition within animal welfare research; the impacts of human-animal interactions involving both staff and visitors; the maintenance of species-specific behaviours and behavioural diversity in ex situ managed populations; and the relationship between animal welfare, visitor experience, and a zoo's social licence to operate. These themes were identified through persistent assumptions in zoo practice, gaps in the empirical literature, and increasing societal expectations for transparency, ethical justification, and measurable outcomes. Across these areas, the paper highlights a recurring challenge: management practices are frequently justified on theoretical or historical grounds rather than validated, applied outcomes, and conclusions from single studies are often overinterpreted despite limited replication or contextual relevance. Our article therefore emphasises the importance of defining credible evidence, critically appraising published research, and adopting replicated, collaborative multi-institutional and mixed-methods approaches. By outlining these research priorities, this paper provides a framework for advancing zoo-based science that can directly inform management decisions, improve animal welfare outcomes, strengthen conservation impact, build public trust and thus future-proof the zoo industry. Ultimately, we argue that the future success of zoos depends on aligning ethical practice, rigorous research, and meaningful visitor engagement through transparent, evidence-driven approaches.