Behavioral Diversity as an Indicator of Good Welfare

The Chicago Zoological Society strives to continuously enhance the welfare of the animals under its care. In the past, zoos tended to focus on negative indicators of welfare (e.g. abnormal behaviors) to assess an individual’s quality of life. However, the absence of negative behaviors or certain physiological markers does not demonstrate that an animal is thriving. Therefore, at Brookfield Zoo, we are committed to incorporating indicators of good welfare that provide insight into an individual’s physical, mental and emotional states. These positive indicators help us regularly monitor an animal’s welfare status and to determine whether the changes we make to management practices really do improve well-being. One way to expand our toolkit for assessing welfare is to integrate behavioral diversity as a measure.

Behavioral diversity—a concept borrowed from ecology—suggests that when an animal in a managed setting (e.g. zoo, farm, sanctuary) expresses a diverse repertoire of species-typical behaviors, they are presumed to have good welfare. For example, we may witness natural behaviors such as a male lion scent-marking his territory or gibbons performing their territorial calls, even though other prides or groups are not present. 

Recent research has examined the relationships between behavioral diversity and traditional measures of welfare. For instance, studies have demonstrated an inverse relationship between behavioral diversity and adrenal activity (e.g. glucocorticoid concentrations), which is often used as an indicator of stress. There is also evidence that behavioral diversity is higher when animals live in stimulating environments or experience positive events. Indeed, previous studies reported that spectacled bears and pandas displayed greater behavioral diversity when given access to new enrichment items and/or climbing structures. In other words, when behavioral needs are met, behavioral diversity is higher. This is why we make sure to provide our animals with various challenges, novel environmental features and the opportunity to make choices. 

In 2016, we initiated a study to examine welfare in chimpanzees. Specifically, we collected behavioral and physiological data from 41 subjects housed across 16 zoos accredited by the Association of Zoos and Aquariums. We utilized these data to examine various models of behavioral diversity. Ultimately, we found that most models had significant negative relationships with glucocorticoid concentrations, and two were inversely associated with stereotypic (i.e. repetitive or abnormal) behaviors. Our findings provide support for using behavioral diversity as a measure of positive welfare.
Based on these results, scientists at the Brookfield Zoo and across the international zoo community will continue to integrate behavioral diversity into welfare monitoring schemes. If you would like to learn more, our new article "Behavioural diversity as a potential welfare indicator for professionally managed chimpanzees (Pan troglodytes): Exploring variations in calculating diversity using species-specific behaviours” (here) details the potential use of behavioral diversity as a positive indicator of animal welfare.

Dr. Jessica Whitham
Animal Welfare Biologist
Published October 28, 2021