Doing better for understudied species: Evaluation and improvement of a species-general animal welfare assessment tool for zoos

Accredited zoos and aquariums are required to have a welfare assessment process in place for the animals in their care. However, welfare assessment theoretical frameworks and methodologies vary widely. Previous studies have shown that taxonomic biases in research are found broadly within the field of animal behavior and specifically within applied animal welfare science, which could translate to taxonomic biases in applied welfare assessment tools. After creating and then using a species-general welfare assessment at Lincoln Park Zoo for 2.5 years, we sought to examine whether there were systematic differences in welfare scores for different taxa. There were 939 Welfare Discussion Tools completed for 174 species between July 2019 and - December 2021, including mammals, birds, reptiles, amphibians, fish, and invertebrates. We found that, broadly, no taxonomic group scored higher than mammals on overall welfare scores, input (resource-based) scores, or output (animal-based) scores. Raters also provided fewer incomplete responses (in the form of "not applicable" or "I don't know" judgments) for mammals than for other taxonomic groups. Integrating these findings with input from welfare scientists, animal caretakers, behavioral husbandry experts and veterinary staff, we modified our original welfare assessment tool to broaden the taxonomic relevance of the tool. Copies of the original tool and the updated/ modified tool are included to serve as a model for institutions developing or revising their own welfare assessment tools.