COVID-19 Changed How Zoo Primates Reacted to Visitors

COVID-19 and changing routines for zoo primates

As the COVID-19 pandemic developed, everyone had to adapt – including zoo animals, which abruptly stopped seeing streams of visitors walk past each day.

A 2022 study examined how primates responded to this change. Researchers assessed the behaviour of bonobos, chimpanzees, western lowland gorillas and olive baboons, finding that their routines altered in several respects, including the time they devoted to resting and eating.

Interactions with visitors are considered important to zoo animal welfare, although they can have beneficial or harmful effects. The researchers therefore wanted to understand what changed when the crowds were absent.

"Primates are some of the most cognitively advanced species in zoos and their interactions with visitors are complex," zoo animal welfare scientist Samantha Ward from Nottingham Trent University in the UK explained at the time.

"A limitation to understanding how visitors can affect behavior of animals in zoos and parks is that they rarely close to the public for prolonged periods, so this provided us with a unique opportunity."

Visitor returns at Twycross Zoo and Knowsley Safari

The observations took place at Twycross Zoo and Knowsley Safari in the UK, both before visitors returned and afterwards.

Across several months, covering multiple periods of opening and closure, primate behaviour changed noticeably, though the effects differed between species.

When visitors started returning to the zoo, bonobos and gorillas spent less time by themselves. Gorillas also rested for less time. After the zoos reopened, chimpanzees ate more and interacted more with their enclosures.

At the safari park, olive baboons displayed less sexual and dominance behaviour once visitors returned. Compared with ranger vehicles seen while the park was shut, they were also more likely to approach visitor cars.

What the behaviour changes mean for animal welfare

Determining whether these shifts were beneficial is less straightforward.

The researchers propose that returning visitors appeared to stimulate chimpanzees and baboons. Bonobos and gorillas spending less time alone might likewise be interpreted positively.

However, it could also be argued that crowds disturbed gorillas – which are naturally more sedentary animals – because they rested less.

When visitors came back, gorillas also altered which areas of their enclosures they occupied most often, indicating that they can manage this disruption to some degree.

"Behavioral changes and changes in enclosure use in the presence of visitors highlights the adaptability of zoo species to their environments," said zoo animal welfare researcher Ellen Williams from Harper Adams University in the UK.

"Provision of environments which enable animals to actively adapt in this manner is really important for their welfare."

The team further found a threshold in visitor numbers for olive baboons. Beyond that point, the animals no longer became progressively more active and stimulated by passing safari park cars.

These findings provide useful information for animal welfare researchers, who recognise that visitors can affect wildlife in many ways – by fostering feelings of companionship and safety, or by causing irritation and even posing threats. Such effects need to be considered in the operation and design of zoos and parks.

Although further lockdowns may not be expected in the near future, hopefully, the research team intends to continue investigating how visitor numbers influence animal behaviour. This will include gathering data from more animals over a longer period.

"Future work could involve looking at the impact on a wider range of species in both zoos and safari parks as well as differences among individual animals," said Williams.

The research was published in Animals.

An earlier version of this article was published in September 2022.