Updated
Adult gorillas have almost no natural predators. The only animal known to kill gorillas is the leopard, and documented cases are rare, mostly involving western lowland gorillas in Central Africa. In Bwindi and the Virunga volcanoes, leopards are now scarce, so mountain gorillas face far greater danger from people, through snares, habitat loss and disease, and from other gorillas, since infanticide by males is a major cause of infant deaths. Here is what threatens gorillas in the wild and how they defend themselves.
Leopards
A silverback can weigh around 160–200 kg, far more than a leopard, so leopards are a risk mainly to infants, juveniles or an animal on its own. Researchers in the Central African Republic have found gorilla remains in leopard droppings, and there are scattered reports from other sites, but attacks are uncommon. In the mountain gorilla parks, leopards were already rare by the 20th century, probably because of hunting and the small size of the forests, and they play almost no role in gorilla deaths today. See our guide to leopards in Uganda.
How gorillas defend themselves
Living in groups is the main defence. The silverback watches for danger, places himself between a threat and the family, and uses displays such as hooting, chest-beating, tearing vegetation and charging, which are usually enough to drive off a rival or a predator. Mothers carry infants constantly for the first months, and juveniles stay close to adults. Each night gorillas build fresh nests, mostly on the ground in Bwindi and in low vegetation, with the group sleeping close together. See our guide to gorilla social behaviour.
Other gorillas
Within the species, the biggest natural danger to infants is infanticide. When a male takes over a group or a female moves to a new group, the new male may kill unweaned infants, which brings the mother back into breeding condition sooner. Fights between silverbacks over females can also cause serious wounds. A strong silverback that protects his group well is one reason females choose to stay with him.
People: the real threat
Humans have been by far the greatest threat to mountain gorillas: forest clearance for farms, hunting in the past, the capture of infants for zoos, which killed adults defending them, wire snares set for other animals, and diseases such as respiratory infections. Today, rangers, veterinary care and tourism income keep these threats in check, and the population has grown to just over 1,000. See our guide to conservation challenges today.
What this means on a trek
Because their main threats are people and other gorillas, silverbacks are naturally alert to strangers. Habituated groups tolerate visitors, but a silverback may still mock-charge if he feels the family is threatened. Stay calm, crouch, look down and follow the ranger. The permit, US$800, or US$600 in April, May and November, pays for the protection that keeps the human threats under control. See our guide to gorilla trekking safety.
Frequently asked questions
Only leopards, and attacks are rare and mostly on young or lone gorillas.
They are rare in the mountain gorilla parks and pose little threat to gorillas today.
Disease, accidents and infanticide by males taking over a group are leading causes.
People, through habitat loss, snares and disease.
