Zoo welfare science is developing rigorous tools to measure animal welfare beyond basic physical health. Behavioural indicators, positive welfare, and quality of life are now central.
Measuring zoo animal welfare has historically focused on absence of disease and stereotypy. Modern welfare science requires evidence of positive mental states - curiosity, play, affiliation. Individual variation means population-level metrics miss suffering in specific animals. Standardised welfare assessment tools, regularly published, are necessary for genuine accountability in zoo animal care.