A new study led by Concordia researchers suggests that carefully habituating wild gorillas to non-threatening humans can help the animals overcome long-term aversions to people in areas with a history of human-led disturbances such as poaching.
The researchers followed a group of 12 western lowland gorillas living on Dipikar Island in Cameroon's Campo Ma'an National Park, a remote area in the country's southern part with a history of poaching and other illegal activity. After closely observing the group over a period of eight years, the researchers found the animals' responses to the presence of humans slowly changed from aggression and avoidance to curiosity and indifference.
The researchers believe these findings could help manage and expand conservation and ecotourism efforts in regions with histories of harmful human activity.
"Habituation has been successful in countries like Uganda, Rwanda and Central African Republic, but usually the process is much quicker," says lead author France Anougue, a PhD candidate under the supervision of Robert Weladji, a professor in the Department of Biology.
She notes that in previous studies, efforts to habituate of gorillas to humans took between 28 and 53 months. Her study required 91 months of near daily contact.
The study was published in the African Journal of Ecology.
France Anougue with Robert Weladji: "Gorillas have the capacity to remember threats posed by poachers, and that fear is passed down to younger members of the group."A slow but fruitful process
The project began with four years of indirect monitoring between 2011 and 2014. Researchers tracked the gorillas from nest to nest, mapped their movements using GPS and identified the group's home range.
The researchers made direct contact with the animals in 2015, using audio cues and vocalizations to announce their presence in non-threatening ways. The group tracked by the researchers included 12 gorillas: a silverback adult male, several adult females, as well as juveniles and infants.
During each encounter, the team recorded the gorillas' first reactions to human observers. Responses were categorized as fear, aggression, avoidance, curiosity or indifference. Researchers also measured how long the animals remained in contact with observers and how much time they stayed in plain sight.
Over the course of the study, the team accumulated nearly 582,000 minutes of contact with the gorillas. As the years passed, the animals spent more time near the researchers and became easier to observe. Fear and aggressive responses steadily declined, while curiosity and indifference became increasingly common.
This behavioural response was correlated to the presence of poachers. Regular anti-poaching patrols collected evidence of poaching activity, such as gunshots, spent cartridges and campfire residue, and shared this data with the researchers. The data showed that harmful human activity decreased as official sensitization work among local communities expanded. These efforts to convince locals of the benefits of protecting the gorilla population and other conservation efforts coincided with increasing habituation.
"Gorillas have the capacity to distinguish between threatening people, such as poachers, and non-threatening people, such as researchers and tourists. 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."
France Anougue with gorilla in CameroonConservation carries multiple benefits
Even though poaching levels in the region are now low and do not seem to impact the animals' daily lives, the gorillas' behaviour suggests that historical poaching and other illegal activities have made them more cautious, even many years later. Overcoming that behaviour can take time, but the results are positive in multiple ways.
"This research shows that protecting gorillas promotes biodiversity, and local communities benefit from the economic spinoffs of increased ecotourism," Anougue says. "Habituation can also help reduce the impacts of climate change through forest regeneration, since gorillas are important seed dispersers that help maintain healthy forests."."She warns that habituation efforts must be maintained if these benefits are to continue.
"Without the daily presence of field teams, tourists and anti-poaching patrols, these populations will become exposed to harm very quickly."
Calvin Fondja, Zacharie Nzooh Dongmo and Marius Sombambo of the World Wild Fund for Nature, the Cameroun Country Program, and Shelly Masi of the Centre national de la recherche scientifique and Université Paris Cité contributed to this research.
Funding for the study was provided by the Zoo de Granby and the Natural Science and Engineering Research Council of Canada.
Read the paper: "Habituation as an Effective Conservation Tool for Western Gorillas in Areas With a History of Poaching"
