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The Weirdness of Zoo Gorillas

The shooting of Harambe in the Cincinnati Zoo serves as a reminder of how strange a gorilla’s life is in captivity.

By Francie Diep


(Photo: Greg Wood/AFP/Getty Images)

Harambe, a western lowland gorilla, was shot and killed this weekend after a three-year-old boy fell into his enclosure at the Cincinnati Zoo. Prior to his death, Harambe had been pawing and dragging the boy around as a growing crowd of onlookers—including the child’s parents—watched in horror, NBC News reports. Zookeepers chose to fatally shoot Harambe rather than tranquilizing him out of a fear that the tranquilizer dart wouldn’t knock the 400-pound gorilla out immediately, and would provoke him to hurt the boy, Ed Hansen, CEO of the American Association of Zoo Keepers, told NBC. Barring such an accident, Harambe would have likely lived many more years in the Cincinnati Zoo. Captive gorillas can live past 50; Harambe was 17.

Harambe’s sudden death, precipitated by a rare accident, serves as a reminder of how strange a gorilla’s life is in captivity. Decades of research has found major differences in how captive gorillas spend their days compared to their counterparts in the wild. This doesn’t necessarily mean gorillas shouldn’t be kept in zoos at all; that’s another argument altogether. Zoo captivity can be beneficial to some species facing extinction, such as western lowland gorillas. But the research on gorillas’ zoo behaviors highlights just how different captivity is for these animals — and how clearly they notice.

Zoo gorillas act differently when there are lots of people visiting their exhibit.

For starters, zoo-bound gorillas are known to eat their feces and regurgitated food. In the 1980s, about 65 percent of zookeepers reported that their gorillas regurgitated and re-ingested their food. One possible explanation for this: It could be a “response to elements of boredom, diet, stress, space restriction, or lack of control in the captive environment,” biologist Kristen Lukas wrote in a review in 1999.

Research has also found zoo gorillas act differently when there are lots of people visiting their exhibit. One 2005 study of the gorillas in a zoo in Ireland found that, on summer weekends — when an average of 1,300 people visited the zoo per day — the apes were more likely to groom themselves, to be aggressive toward one another, and to clench their teeth repetitively and rock back and forth. On winter weekdays, when 10 or fewer people would visit daily, they spent significantly more time resting. A 2011 study of another zoo’s gorillas found that, when it was busier and noisier in their enclosure, the apes were more likely to stare, posture, and charge at people.

There are ways to reduce these weird zoo behaviors, but the science is still uncertain and the strategies don’t work 100 percent of the time. The 2011 study found that privacy screens significantly cut down on gorillas’ propensity for posturing and charging at zoo-goers. More recently, researchers have looked at whether training gorillas to perform simple tasks, such as showing a zookeeper their shoulder or tongue, might help. The idea is that such training might be interesting and enriching for the gorillas. Small studies have been promising, but so-called positive reinforcement training hasn’t yet been rigorously evaluated for gorillas, researchers wrote just this month in the journal Animal Behavior and Cognition.

Perhaps this latest incident will serve as a catalyst for that work.