Behaviour 2019
Evaluating the Welfare of Bettongs and Armadillos in Response to Changes in Zoo Exhibit Lighting
Natasha K. Wierzal, Jason D. Wark, Katherine A. Cronin. Lincoln Park Zoo, Chicago, IL, United States

The maintenance of a circadian rhythm is a highly conserved trait across vertebrates, and there is no bodily process, mental, emotional, or physical, that is not in some way impacted by the circadian rhythm. Light is the strongest external cue used to synchronize an animal’s internal rhythm to the environment. Therefore, when assessing the welfare of animals in zoos, exhibit lighting is especially important. We analyzed the behavior of two nocturnal species, brush-tailed bettongs (Bettongia penicillata, n = 2) and a La Plata three-banded armadillo (Tolypeutes matacus, n = 1) housed on reverse light cycles in response to dimmed exhibit lighting and the addition of twilight phases to their light cycles. While behavioral results varied, additional assessments on the bettongs, including 24-hour activity monitoring and object recognition tests, indicated a positive impact on welfare following light modifications. The findings indicate that altered lighting alone is likely not sufficient to maximize welfare, but lighting does impact welfare and should be considered when determining best practices for housing nocturnal animals.