Welfare of Animals in Zoos - The Five Domains Model

The Five Domains model has largely replaced the Five Freedoms as the primary framework for assessing and improving welfare in zoo animals, offering a more nuanced and positive welfare-oriented approach.

Key Facts

The Five Domains (nutrition, physical environment, health, behaviour, mental state) were developed by David Mellor in the 1990s and updated through to 2017
The model emphasises not just the absence of negative experiences but the provision of positive welfare states
Zoo accreditation bodies including BIAZA, EAZA, and AZA increasingly use Five Domains assessments in their standards
Behavioural opportunities are emphasised: the ability to perform natural behaviours is central to good welfare
Mental state - including boredom, fear, frustration, and positive engagement - is explicitly addressed as a welfare domain
The model helps zoos move beyond reactive welfare (treating problems) to proactive positive welfare provision

Welfare Considerations

The Five Domains model represents a significant advance in zoo welfare science because it explicitly addresses subjective mental states and positive experiences, not just physical needs. A zoo animal that is fed correctly and free from disease may still experience chronic boredom, frustration, or fear if its behavioural and cognitive needs are unmet. Implementing the model requires zoos to invest in species-appropriate enrichment, social groupings, space, and naturalistic environments. When applied rigorously, it drives meaningful improvements in captive animal quality of life.

What You Can Do

Support zoos that publish welfare assessments and commit to Five Domains standards
Ask zoos about their enrichment programmes and how they assess mental state
Visit accredited institutions (BIAZA, EAZA, AZA) that commit to welfare standards
Avoid facilities that lack accreditation or show stereotypic behaviour in animals