When people visit a zoo, they often focus on observing the animals.
But an important scientific question has also been asked:
How do the animals experience us?
A scientific review published by the Zoo Animal Welfare Education Centre (ZAWEC) examined decades of research on what is known as the “visitor effect”—the influence that zoo visitors may have on the behavior and welfare of captive wild animals.
The findings are nuanced.
The evidence shows that visitor presence can affect animals, but those effects are not the same for every species or every individual. Some animals appear relatively unaffected, while others demonstrate increased vigilance, avoidance, aggression, changes in activity, or physiological signs consistent with stress.
Researchers also caution that an animal becoming accustomed to people should not automatically be interpreted as evidence of good welfare. Habituation simply means an animal reacts less visibly—it does not necessarily indicate that its welfare has improved.
One of the strongest themes throughout the review is the importance of choice and control.
Animals that can choose when to be seen, when to retreat from public view, and how closely to interact with visitors are generally better able to cope with human presence. Enclosure design, quiet areas, visual barriers, and opportunities to withdraw all play important roles in promoting positive welfare.
Perhaps the most important takeaway is that modern animal welfare science is moving beyond asking whether visitors influence zoo animals.
Instead, it increasingly asks:
How can zoological facilities provide environments where animals retain meaningful choice, control, and the ability to avoid unwanted human interactions?
Understanding wildlife involves more than observing animal behavior.
It also requires asking how our behavior shapes their lives.
