Zoo elephants are fascinated by human visitors — but frogs are unimpressed, study finds

Visiting a zoo is one of the best places to ponder the points of view of animals. How do they feel about being locked in a cage? Are they happy or unhappy in their current lives? And, perhaps somewhat selfishly, what do these animals think of us — the humans who are observing them?

A recent study published in the scientific journal Animals sheds light on that last question by comprehensively reviewing 105 papers that have been published on the subject since 2012. In the process, researchers learned some surprising details about animals in zoos — particularly, that animals like elephants seem to react warmly to humans' presence, while animals such as frogs do not.

While many of the aggregated studies had small sample sizes, the authors were able to boil down their behavior into three categories of animal reactions to human visitors' presence: Positive, featuring "increased interest in visitors [and] visitor areas, working to gain attention from visitors or moving to be closer to visitors"; negative, in which the visitor acts as "a source of stress to the animals, which is usually evidenced by responses such as an increase in visitor avoidance," or neutral, which is what it sounds like: no visible behavioral or physiological change to human visitors' presence.

Overall, the animals studied across the various papers found that out of 302 interpretations of reactions to visitors' behavior, "53% were neutral, 21% were negative, 21% were 'unclear' and only 4% were considered to be positive."

Elephants (Proboscidea) were among the handful of animals that seemed to positively respond to the presence of people, with the authors writing that "Proboscidea are the largest land mammals, and so this could have led to a reduced effect of zoo visitors. It would be expected that zoo visitors would be drawn to elephants, as a large flagship species."

Similarly parrots (Psittaciformes) reacted positively to human visitors because "parrots are highly intelligent birds who are known for their need for interaction and attention, and for their desire to interact with visitors in zoo environments. The positive valence recorded in this review could thus be a product of birds trying to gain attention from and seeking interactions with zoo visitors, as was recorded during the COVID-19 pandemic." Elephants and parrots were alone among the various animal species that reacted positively to human visitors' presence more often than can be attributed to chance.

By contrast, animals like scaled reptiles and frogs behaved in a way that the authors found "cryptic," although they noted that the animals may have clammed up around humans because "visitors could potentially be perceived as a threat." There was less ambiguity in interpreting the behaviors of other animals, though, the ones for whom the authors found that human visitors had a "negative impact." These included flightless birds, odd-toed ungulates (such as horses and rhinoceroses), even-toed ungulates (such as camels and hippopotamuses), ostriches, marsupials (such as kangaroos and wallabies) and hedgehogs.

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Although the study focused on 252 non-primate species, the scientists did also discuss what other studies have found about primate reactions to zoo visitors. "Studies have reported changes in primate behaviour in response to visitors, with visitors being recognised as a stimulant for some primates but a negative stressor for others," the authors write. Primates are generally found to be upset by large groups of noisy visitors, and primates with smaller body sizes similarly tended to be more human-averse than larger primates.

In addition to the fact that there are not many studies about non-primate species reacting to zoo visitors' presence, the authors noted another limitation of their study: The fact that any so-called "experiments" on how zoo animals react to humans are by their very nature opportunistic, and therefore by definition not controlled.

"Although there has been an increase, the majority of work is opportunistic, looking at numbers of visitors and comparing that using correlational methods to animal behaviour," the authors explain. "Controlled experimental setups might help to more clearly disentangle the range of factors which may impact on animal behaviour in zoos, from the true impact of visitors on animals."

When it comes to the news that elephants and parrots are more likely to respond favorably to human visitors' presence, it is notable that both species are extremely intelligent. Speaking with Salon last month about elephants, Dr. Paula Kahumbu, the CEO of the charitable organization Wildlife Direct, described how their intellect is discernible through their mourning rituals.

"They will repeatedly return to dead elephants or relatives, dead relatives, and they will come towards them," Kahumbu told Salon. "They will touch them, feel them. If an elephant has recently died or is dying, they will even try to raise it, or they will stand around and just be with a dying elephant. Once an elephant has died, they will sometimes even cover it up with bushes. It's a really peculiar thing."

Parrots, similarly, are so intelligent that they can learn to dance without being taught. According to a 2019 study performed on a white cockatoo named Snowball who had been taped dancing to the song "Everybody," the parrot showed a similar amount of intelligence and creativity when dancing to the songs "Girls Just Wanna Have Fun" and "Another One Bites The Dust."

"Parrots are unusual because these complexities are coming together in their brains," Aniruddh Patel, a psychologist at Tufts University and Harvard University, told CNN at the time. "When these capacities come together, it leads to the impulse to dance."

While research on zoo animals and their perceived preferences for visitors is limited, it's also biased towards "charismatic species," the study authors conclude. We still have a lot to learn about what animals think of us, which is not only a reflection of their unique intelligence, but our own.