When Dian Fossey began her pioneering studies of mountain gorillas 50 years ago, she soon realized that in order to study the gorillas and their behaviors in detail, she would have to find ways to get them used to her close presence in the forest. This process is called habituation and now all the mountain gorilla groups protected and studied by the Fossey Fund in Rwanda are habituated to the presence of humans, such as our trackers and scientists. Our staff still keep a fixed distance from the gorillas, however, and some gorillas are more relaxed around humans than others, but all are used to the presence of people.
Recently, though, while one of the gorilla groups we monitor traveled far over the border of neighboring Congo, where our trackers could not follow, they returned a few weeks later with a new female – one who had never been seen before and had clearly not been habituated to human presence. She originated from a non-habituated group in Congo and was in for a surprise when the group returned to our monitored area! Our staff estimated her to be about 9 years old, based on her size.
At first, the new gorilla – who does not yet have a name – was fearful when she saw her first humans, quickly ran under a bush and hid there until our trackers had left. This routine continued for about three to four weeks and then she started to become accustomed to seeing our trackers.
Habituating a whole group would take much longer, says Veronica Vecellio, the Fossey Fund’s gorilla program manager in Rwanda. But since the other gorillas in this group were already habituated to the presence of humans, it seems that the new female was able to adapt much more quickly.
What habituation means
“We were very careful at the beginning to avoid walking too close to this group and we made ‘belch’ vocalizations each time, to announce our presence,” says J.P. Samedi Mucyo, the Fossey Fund’s monitoring and protection officer in Rwanda. “We were pleased to see the new female playing with other gorillas and being well tolerated in the presence of the young dominant silverback, Twibuke,” he says.
The process of habituating wildlife is not the same as domesticating them, as is done with pets. Rather, it is a way of getting the animals to act normally even though there may be some humans in the general area. “When we are with the gorillas, we feel as though we are an integrated part of the environment, such as a tree or another harmless animal. The gorillas don’t interrupt or modify their behaviors because we are there,” says Vecellio.
Habituating a whole group of gorillas can take several months to several years, says Vecellio, although with mountain gorillas the process tends to go faster than elsewhere. This is probably because the unique terrain, including steep slopes, lower vegetation and uneven tree canopy allow for easier visibility and gradual approaches by humans and thus a smoother tolerance process.
Our staff expects that within a few more weeks, the new female will tolerate the presence of humans just as do the other gorillas in her group, and will then be able to enjoy a peaceful time in her new group. She will receive a name during the annual “Kwita Izina” naming ceremony to be held in Rwanda in September, along with all the infants born during the past year.