For many, the word gorilla brings mental images of King Kong scaling the Empire State Building while beating his chest and roaring. The movies, coupled with most people's general ignorance, have been largely responsible for a collective belief that gorillas are aggressive and dangerously wild creatures. Research and interaction with these creatures has revealed otherwise. Far from being violent without provocation, these animals tend to be peaceful, gentle creatures that share many traits with their nearest cousins - mankind.

General Information

The gorilla is the largest of the species that makes up the primate family (which also includes monkeys, chimpanzees, orang-utans - and, of course, humans). The gorilla species is generally divided into two sub-species:

• The Western gorilla, which incorporates:

  • The Western lowland gorilla (Gorilla gorilla gorilla)
  • The Cross River gorilla (Gorilla gorilla diehli)

• Eastern gorilla, including:

  • The Mountain gorilla (Gorilla beringei beringei)
  • The Bwindi Forest gorilla (Gorilla beringei graueri)
  • Eastern lowland gorilla (Gorilla beringei graueri)

Though there are a few minor differences between sub-species, which can be accountable to their differences in habitat, they are generally believed to have evolved from the same single species of gorilla.

Gorillas can be found in eight countries in central and west Africa. The western lowland gorilla is found in the Democratic Republic of the Congo, Cameroon, Gabon, the Central African Republic, and Equatorial Guinea. The eastern lowland gorilla is found in the east of the Democratic Republic of the Congo, while the mountain gorilla, the rarest of all, is found within limited mountainous regions of the Democratic Republic of the Congo, Rwanda and Uganda.

From Blackback to Silverback

Baby gorillas are born at around five pounds in weigh, with soft, brown-black hair that darkens and thickens as they mature. Like chimpanzees, gorilla babies mature about twice as fast as human babies of the same age, though human babes develop skills beyond that of their primate cousins. Up to the age of six they are classed as juveniles and both sexes have thick black hair.

Females tend to mature faster than males; by the time they are eight years old they are ready to leave the group of their birth and join a new gorilla group. By the age of ten they are ready to give birth to their first child, and they can continue to conceive other children, one at a time and usually at around three or four years apart.

Males, conversely, leave their birthgroup at around 11 years old, though they tend to live alone for a few years. By the age of 15, the male will have developed a batch of grey hair, which leads to them being given the name 'silverbacks'. At this stage, they are ready to begin the formation of their own social group.

The Society of Gorillas

Like all primates, gorillas are very social creatures, living in small family groups of adult males and females. Unlike monkeys, however, gorillas tend to leave the group they were raised in to form new groups. Each mini-society revolves around an adult male, the most dominant silverback, with other males deferring to the chief silverback's leadership. It is the role of each silverback to protect his own family from intruders and predators. Poachers trying to kidnap a baby gorilla often find they must kill the silverback father - and often the mother too - before they are free to take the baby. Such actions have a devastating effect upon the gorilla community. The larger group often find themselves dispersing to form smaller groups around other silverbacks. As his first display of dominance, the new silverback leader will often kill the offspring of his predecessor to protect his own line of descendents (though brutal-sounding to us, this is a common practice for many animals).

Language

Gorillas communicate to each other via a combination of vocal sounds and body language. Gestures that humans might consider friendly, such as smiling, can be interpreted by gorillas as aggressive or confrontational (silverbacks often bare their teeth to warn off other gorillas). The noises made by gorillas are similar in many ways to those of humans. They can be heard to laugh when happy, burp when satisfied by a good meal, roar when angered or scream when frightened. Despite these many similarities, humans never invite gorillas to tea.

Food and Drink

The gorilla diet is mainly vegetarian, they live off roots, leaves, vines and fruit. These plants provide the animals with their primary source of water. They will also eat grubs, larvae, worms and other insects, which provides them with a rich source of protein.

Time Running Out

All three types of gorilla have been listed as endangered species. Life is already fragile for gorillas. The life expectancy of a healthy gorilla is about 40, roughly two-thirds that of a human, though infant mortality is much higher. Many baby gorillas die within their first year of life. Nearly half will die before they become adults, due to disease, accident or infanticide at the hands of another gorilla. With mankind's encroachment upon their environment, their life expectancy is significantly reduced. Economic greed has led to the destruction of the gorilla's habitat, while commercial bushmeat hunters and the wider effects of civil war in central Africa are still responsible for the slaughter of nearly 3,000 gorillas each year. There are just 50,000 western lowland gorillas still living in the wild; just 2,500 eastern lowland gorillas - and about 600 mountain gorillas worldwide.

Thanks to the efforts of people like Dian Fossey, the rapid extinction of the mountain gorillas seems to have been slowed, though they are still very much on the critical list as a species, due to changes in the environment and the constant threat of hunters.

Further Reading

• Last Chance to See by Douglas Adams

• The World Society for the Protection of Animals

• BBC Extinction Files