Making Animal Welfare Assessments More Inclusive

To meet accreditation requirements, zoos and aquaria are required to regularly measure the welfare of animals in their care. However, some experts feel that there is not enough clear guidance on how to carry out these assessments and which species to consider. 

Most welfare assessments are “species-general,” meaning the questions are applied to all animals uniformly (for example, measuring octopus welfare and lion welfare using the same factors, even though these animals are extremely different). The authors of this study point out that species-general measurements can bias welfare assessments toward animals that are more familiar to humans.

To address this, the authors tested a species-general assessment called the Welfare Discussion Tool (WDT) at Lincoln Park Zoo from 2019-2021. The WDT measures 41 welfare factors including “inputs” (resources provided to animals such as enclosure, diet, and enrichment) and “outputs” (how the animals present). Three professionals were asked to complete the WDT at least once per calendar year covering 174 species. For most species, this meant filling out a separate assessment for each individual animal (e.g., for every tiger in an exhibit). For a select few species (e.g., cockroaches), assessors calculated a group score as they could not measure animals individually.  

Because they wanted to know whether the WDT is biased toward certain types of animals, the authors were especially interested when assessors responded “I don’t know” or “not applicable” — and whether certain species received these responses more than others. At the end of the study, they offered ways to revise the WDT to make the process more inclusive to all animals.

The results showed that mammals scored significantly higher on the WDT than birds and fishes when looking at overall scores and inputs only. When looking at outputs only, mammals scored significantly higher than birds. Additionally, raters provided fewer “I don’t know” and “non-applicable” responses for mammals, while invertebrates received the highest number of such responses. Finally, species whose members were assessed individually also scored higher than species who received “group” scores when looking at overall scores and inputs, but not outputs. 

The authors present several possible reasons for the observed higher scores in mammals:

1. The WDT unintentionally favors mammals. Extensive knowledge and experience with mammals might have influenced the tool’s design, making it more suitable for assessing mammal welfare.
2. Raters have a bias towards mammals. The increased interaction and connection between caretakers and mammals compared to other species might have led to more positive assessments. 
3. Our familiarity with mammals alters our understanding of welfare. Our similarities to other mammals can affect how we perceive their welfare. This bias could either originate from the raters themselves or the creators of the WDT. 
4. Mammals in zoos may have better welfare compared to other taxonomic groups. The abundance of research on mammal welfare may contribute to a greater understanding of their needs and care. However, it remains uncertain whether mammals genuinely experienced superior welfare or if the ratings were influenced by the other factors listed above.

The authors argue that the lack of unsure responses and the higher scores for mammals support their hypothesis that welfare assessments tend to be biased against understudied animals. To be more inclusive, they recommend revising language used in assessment forms to apply to a wider range of animals; including welfare indicators such as UV lighting, use of space, and sensory outputs that are more common within non-mammals; and structuring assessments so that raters cannot easily choose “not applicable” when they’re not familiar with a species.

In conclusion, the results of this study highlight the importance of researching a wide range of animal species, especially those that haven’t received much attention in the past. This is because a poor understanding of animal welfare can easily result in poor caretaking. From an advocacy standpoint, it’s important to push zoos and to use more inclusive measurements so that they can accurately address their residents’ welfare needs. More comprehensive assessments may also benefit animal sanctuaries and rescues that house diverse species.