Modern zoo welfare assessment is moving beyond measuring absence of suffering to actively measuring positive welfare states — joy, curiosity, play, and social engagement — in captive animals.
The shift toward positive welfare indicators in zoos represents a genuine conceptual advance: the goal is not merely to avoid suffering but to actively promote flourishing. Animals that are free from negative states but also engaged, curious, and socially fulfilled are living qualitatively better lives than animals that are simply not sick. Developing reliable, validated positive welfare indicators for the diverse species held in zoos is scientifically challenging but increasingly well-supported by research. Zoos that invest in individual-centred enrichment, maintain stable social groups, and give animals meaningful choices over their daily environment are best placed to achieve positive welfare across their collections.