Evidence-based zoo animal welfare assessment: Putting science into practice

Abstract

This comprehensive review explores evidence-based strategies for assessing and enhancing animal welfare in modern zoos and aquariums. The two primary objectives are to explore the ways in which understanding behavioural biology and natural history of a given species can enhance zoo animal welfare assessments and discuss how current knowledge of fundamental principles regarding animal behaviour and physiology can help identify and validate welfare indicators. Species-specific protocols, generic protocols and risk assessment methods are examined and the complexities of using natural behaviour as a welfare indicator are explored, acknowledging the inherent challenges of comparing captive and wild behaviours. Behavioural indicators as predominant tools in welfare assessment are analysed for their selection, development and validation. Challenges such as observer bias and external influences are discussed, highlighting the importance of ongoing research and collaboration for refining behavioural indicators. The review extends to physiological indicators, focusing on their diversity and complementarity with behavioural assessments. The selection process involves consideration of species-specific characteristics, biological matrices and sampling methodology. Challenges in the validation of physiological indicators are discussed, underlining the need for comprehensive studies. In conclusion, this review advocates for an integrated, evidence-based approach that combines behavioural and physiological indicators, acknowledging the challenges and offering practical insights for advancing animal welfare in zoo settings.