Having humans nearby is a double-edged sword for rare, charismatic species.

On the one hand, humans are often the biggest threat, either indirectly by destroying habitat, or directly through poaching and wildlife trafficking. On the other side, the regular presence of people such as tourists and police can be the best defense against the depredations of other humans.

The gorillas of Cameroon’s Dipikar Island encapsulate both sides of this story. For years, poaching depleted their numbers, leaving the animals skittish and unwelcoming when humans approached. But new research shows that even gorillas battered by these human incursions can learn to accept well-behaved people, and the protection that comes with them.

The new work, published earlier this year in the African Journal of Ecology, shows that “gorillas have the capacity to distinguish between threatening people, such as poachers, and non-threatening people, such as researchers and tourists,” says lead author France Anougue, a Ph.D. student at Concordia University in Montreal. Without the daily presence of such people “these populations will become exposed to harm very quickly.”

That doesn’t mean such tolerance came quickly or easily. Scientists working in other parts of Africa have found that gorillas can become accustomed to having people nearby in as little as 28 months. But that research happened in protected areas with populations that hadn’t endured intensive poaching. When scientists in Cameroon began their work with a group of 12 gorillas, it wasn’t clear the animals there would be so accepting.

The change took years. From 2011 to 2014, researchers backed by the conservation group the World Wildlife Fund, which has promoted gorilla-related tourism, tracked this gorilla band from a distance to understand their movements and habits. The extended gorilla family they followed included a single senior male—a so-called silver back, and depending on the year, 3 or 4 adult females, 1 or 2 subadults, 2 to 3 juveniles and 1 to 3 infants.

Starting in 2015, scientists and local trackers started trying to get closer to the gorillas, and to monitor the animals’ reactions. The people would approach the gorilla group while clacking their tongues or snapping their fingers to draw attention. As soon as the animal’s noticed them, the people would mimic gorilla-eating behavior and acting in a “neutral” way, the scientists wrote.

In the first few years, the gorillas greeted the people with shows of aggression nearly 30% of the time. More than 30% of the time they responded with fearful behavior. They rarely showed curiosity or indifference.

But as the years went by and the research continued, those patterns gradually flipped. By 2022, 7 years after starting, the gorillas rarely showed fear or aggression when people were nearby. Rather, they showed curiosity more than 30% of the time and disinterest roughly the same amount.

“We also observed this tolerance in younger gorillas, suggesting that behaviour is learned from other members of the group,” says Anougue. “Gaining their trust was not easy.”

These increased encounters with benign humans, paired with stepped-up poaching patrols, were also accompanied by a decline in poaching activity. Signs of poaching such as gunshots, bullet casings and campsites fell roughly by half between 2015 and 2022. Still, it’s not clear to what degree this decline in poaching was the result of the researchers’ presence or the related increase in poaching patrols and local awareness of the conservation work.

For Anougue, the results show the behavioral resilience of gorillas, which can overcome past traumas and learn to tolerate nearby people. That, in turn, could help better both their chances of survival and the economic fortunes of nearby humans. “This research shows that protecting gorillas promotes biodiversity,” she said, “and local communities benefit from the economic spinoffs of increased ecotourism.”

Anougue, et. al. “Habituation as an Effective Conservation Tool for Western Gorillas in Areas With a History of Poaching.” African Journal of Ecology. April 28, 2026.

Photo: USAID Biodiversity & Forestry via Wikimedia