Stephanie Allard, Ph.D., is the Director of Animal Welfare for the Detroit Zoological Society and oversees the Center for Zoo Animal Welfare.

Glass enclosures like those in the Holden Reptile Conservation Center at the Detroit Zoo are designed to provide visitors with less obstructed views of the animals and bring them even closer. These clear barriers can also easily lend themselves to direct contact by both the visitors and the animals – visitors can press their hands and faces right up to the glass, and even knock or bang on the glass. As it appears to be a common occurrence in zoos and aquariums, it’s important to us that we understand what effect, if any, that this visitor behavior has on the animals.

While this topic has not been well researched thus far, the Center for Zoo Animal Welfare at the Detroit Zoo is in the midst of a study designed to determine if there is an impact on the welfare of reptiles when visitors knock on the glass of their enclosures.

We first wanted to determine if there were specific enclosures or species that were being targeted by visitors, and we learned that this was not the case. Next, we want to determine if there is a behavioral response by the animals to the visitors interacting with the glass. We recorded video footage of the individuals before and after visitors interacted with the glass of the enclosure. We are currently comparing that behavioral data to other data collected at times during which there were no visitor interactions.

Based on what is known about reptiles, we may find in this study less behavioral evidence of their reactions to their environment. But an important thing to keep in mind is that just because we can’t see a reaction, it doesn’t mean the individual animal isn’t affected.

Therefore, the final phase of this study will attempt to look for any changes in hormone levels – specifically corticosterone, which is the reptile and avian equivalent to cortisol in humans – during times with little to no visitor interactions and those with more. This part will be a bit trickier, as the means by which we collect hormone information non-invasively in mammals – by measuring levels in feces or saliva, for example – is not as easily done with reptiles. We are excited by the challenge however, as the welfare of every animal is important, including the ones that people might not relate to as easily.

– Dr. Stephanie Allard