Table 1.

Summary of welfare assessment frameworks and protocols that have been applied to zoos with references for their use in zoological collections.

Assessment Framework	Features	References and Species Examined
Five Domains	Criteria listed under 4 physical domains: Nutrition Environment Health Behavior Resultant 1 mental health domain	Multiple species [3]
European Welfare Quality®	4 principles: Good feeding Good housing Good health Appropriate behavior Principles defined by a set of 12 criteria	Bottlenose Dolphins [36] Dorcas Gazelles [37] Pygmy Blue-tongue Skink [10]
Universal Animal Welfare Framework	Four components: Institutional philosophy and policy Programmatic structure and resources Execution Evaluation.	None-overarching philosophy [16]
Opportunities to Thrive program	Flips the Five Freedoms to transform them to focus on attainment of positive affect: Opportunity for a well-balanced diet Opportunity to self-maintain Opportunity for optimal health Opportunity to express species-specific behavior Opportunities for choice and control	Hawaiian Endangered Birds-multiple species [38]
Animal Welfare Assessment Grid	Four components: Physical health Procedural Parameters Environmental comfort Psychological wellbeing	Zoo primates and birds [43] Giraffe, Scimitar horned oryx and large felids (tigers, leopards and cheetahs) [13] Western Lowland Gorillas [44]