As zoos worldwide strive to improve animal welfare, there’s growing recognition that simply preventing negative experiences isn’t enough — facilities must also promote positive welfare states. For carnivores in particular, this shift is crucial given historical challenges with keeping these species in captivity, as they’re prone to developing stereotypies (abnormal repetitive behaviors) such as pacing. While previous research has often focused on reducing problematic behaviors, less is known about how to encourage positive welfare indicators in zoo-housed carnivores.

The present study examined whether natural biological characteristics (like habitat preferences and body size) or husbandry factors (like age and enrichment) better predict positive behaviors in carnivorous species. The researchers analyzed data from previously published studies, looking specifically at three indicators of positive welfare:

1. General activity levels;
2. Play behavior; and
3. Engagement with the environment.

The analysis drew from a large dataset encompassing multiple carnivore species, such as polar bears, tigers, lynxes, red foxes, wild dogs, otters, seals, and sea lions. For activity measurements, the researchers analyzed data from 136 individual animals representing 23 different species. Environmental interaction data came from 55 individuals across 15 species, while play behavior data was collected from 27 individuals representing 7 species. To ensure scientific rigor, the researchers only included studies that provided complete behavioral data expressed as percentages of time spent in these activities.

The research team employed a sophisticated statistical approach to account for the evolutionary relationships between different carnivore species. This was crucial because closely related species often share behavioral traits that could impact the results. The analysis was conducted at two levels: examining behaviors of individual animals while controlling for their species relationships, and looking at broader species-level patterns using median values for each behavior.

The findings were particularly noteworthy in what they didn’t show: none of the biological variables predicted positive welfare behaviors. The researchers tested multiple natural history characteristics, including:

• Latitudinal range (indicating habitat flexibility)
• Number of natural habitats occupied (suggesting adaptability)
• Social structure
• Body weight

At both the individual and species level, these innate biological factors showed no significant correlation with rates of positive behaviors.

Instead, the study found compelling evidence for the importance of husbandry practices. When zoos provided additional enrichment beyond baseline levels, animals showed significantly higher rates of activity and environmental interaction. These enrichment effects remained consistent across species, suggesting that appropriate husbandry can promote positive welfare regardless of a species’ natural history.

Age also emerged as a significant predictor, with both activity levels and play behavior showing marked decreases in older animals. The mean age of the social group was negatively correlated with activity and play.

The study had some limitations, including relatively small sample sizes for certain behaviors (particularly play) and the fact that many published studies lacked complete husbandry information, which led to some data being excluded from analysis.

However, these findings still have important implications for zoo management practices. They suggest that no species of carnivore is inherently unsuited to captivity from a positive welfare perspective. Rather, the key to promoting positive behaviors lies in appropriate husbandry — particularly through providing enrichment opportunities. While the natural decline in activity and play with age should be considered when assessing welfare, the strong positive effect of enrichment indicates that zoos can successfully promote positive experiences across carnivore species through proper environmental provisions.

For animal advocates and zoo professionals, this research emphasizes the value of enrichment programs in supporting positive welfare. Future studies would benefit from examining additional measures of positive welfare, such as anticipatory behavior and cognitive bias, to build an even more comprehensive understanding of how to help carnivores thrive in zoo environments.