Can You Hear Me Now?
Although normally very quiet, gorillas make over 20 different vocalizations including roars and growls of aggression, grunts and barks to coordinate group activity and movement and loud hoots that may serve to warn other gorillas away.
Sleeping in the Trees
Each night, gorillas build sleeping nests by bending branches and leaves down to form a platform. These nests keep the gorillas off the cold ground and support them in the trees during the night. They build a new nest each night as they travel around in search of food.
The gorilla’s large size and the relatively low nutritional value of their diet means they must spend many hours each day feeding in order to maintain their body weight. An adult male gorilla may eat as much as 40 pounds of vegetation in a day. Gorillas have powerful jaws and large teeth needed to grind up the tough plant material in their diet. Gorillas rise early and spend the morning foraging and eating. During the hottest part of the day they rest before beginning to eat again until the sun goes down. In the dense forests, gorillas normally don’t have to travel very far to find enough food.
Gorillas are quadrupedal, meaning they walk on all fours. They walk on the soles of their back feet, but curl the fingers of their hands under and walk on their knuckles. Walking on their knuckles provides strong support for their long arms, and their massive arm, shoulder, and neck muscles.
- Western lowland gorillas are four and a half to five and a half feet (1.4-1.75 m) tall.
- Males weigh 300-600 pounds (136-272 kg), females are smaller weighing 154-300 pounds (70-136 kg).
- Their fur is predominantly black with a brownish tinge and a reddish-brown cap on top of the head.
- Adult males develop silver colored fur on their backs.
- They have an opposable thumb on their hands and an opposable big toe on their feet.
What Does It Eat?
In the wild: Leaves, shoots, pith, stems and fruit.
At the zoo: Vegetables, fruits and primate biscuits.
What Eats It?
Leopards prey on the gorilla. The young are often preyed on by raptors, and un-weaned infants may be killed by male gorillas when they displace a former male leader.
Gorillas are social animals that live in family groups consisting of an adult silverback male, several adult females, and their offspring. Family groups may number from 2 up to 35 individuals but usually consist of five to 10 animals. The adult male and females usually stay together for life while the young leave when they reach maturity. Fighting plays an important role in group hierarchy, though no territorial defenses are exhibited.
Female gorillas are sexually mature at about seven to eight years of age but usually do not breed until they are ten. Males mature somewhat later and do not breed until they attain silverback status after age 15. Gorillas do not have a distinct breeding season. After a gestation of 250-290 days females give birth to a single infant weighing four to five pounds (1.8-2.3 kg). Twins are rare. Infants are carried against the mother’s chest and later on her back. They begin to crawl at about nine weeks and can walk at 30-40 weeks. Gorillas are weaned between three and four years of age. All members of the gorilla group share in raising and protecting the young. Both males and females normally leave their natal group at about ten years of age. Females may join with an existing group or join with a solitary male to form a new group. Males usually find an area to live in and then attract young females. Western lowland gorillas live between 30-40 years in the wild and up to 50 years in captivity.