The gorilla, the largest of the primates, is a ground-dwelling herbivore that inhabits the forests of central Africa. There are two species of gorilla, both in the genus Gorilla.
Gorillas move about by knuckle-walking . Males range in height from 1.65 m to 1.75 m, and in weight from 140 kg to 165 kg. Females are about half the weight of males.
Gestation is 81/2 months. There are typically 3–4 years between births. Infants stay with their mothers for 3–4 years. Females mature at 10–12 years (earlier in captivity); males 11–13 years, sometimes sooner if they assume leadership early. Lifespan is between 30–50 years.
The Philadelphia Zoo's Massa set the longevity record of 54 years at the time of his death.
Both species of gorilla are endangered, and have been subject to intense poaching for a long time. Threats to gorilla survival include habitat destruction and the bushmeat trade.
A silverback is an adult male gorilla, typically more than 12 years of age and named for the distinctive patch of silver hair on his back, that has large canines that come with maturity. Blackbacks are sexually immature males of up to 11 years of age.
Silverbacks are the strong, dominant troop leaders. Each typically leads a troop of 5 to 30 gorillas and is the center of the troop's attention, making all the decisions, mediating conflicts, determining the movements of the group, leading the others to feeding sites and taking responsiblity for the safety and well being of the troop.
Males will slowly begin to leave their original troop when they are about 11 years old, travelling alone or with a group of other males for 2–5 years before being able to attract females to form a new group and start breeding. While infant gorillas normally stay with their mother for 3–4 years, silverbacks will care for weaned young orphans.
If challenged by a younger outside male, he will scream, beat his chest, shake broken-off branches at the intruder, bare his teeth then charge forward. If he is killed by disease, accident, fighting or poachers, the group will split up or be taken over in its entirety by a male descendant or even an unrelated male; there is a strong risk that a new male may kill the infants of the dead silverback.
Gorillas are closely related to humans and are considered highly intelligent. A few individuals in captivity have been taught a subset of sign language (see animal language for a discussion) such as Koko, also known for being the only animal known to keep one of another species as a pet. Koko has taken care of several companion cats over the years.
Primatologists continue to explore the relationships between various gorilla populations. The most recent publication (Primate Taxonomy, Colin Groves 2001 ISBN 1-56098-872-X) lists two recognized species, with four subspecies:
Gorilla gorilla, Western Gorilla
Gorilla beringei, Eastern Gorilla
- Gorilla beringei beringei, Mountain Gorilla
- Gorilla beringei graueri, Eastern Lowland Gorilla
Gorillas in pop culture
- The gorilla suit is an eternally popular gag costume. On The Zone on YTV, a recurring character is Gorilla Stan , who is actually a person wearing a cheap Halloween costume.
- Optimus Primal on Beast Wars and Beast Machines starts out as a regular gorilla. His beast modes get more technological in each incarnation.