They can be identified by their unique noseprints - no two gorillas have the same nostril shape or pattern of ridges. They communicate with each other by chest-beats if they are excited or alarmed, soft purring sounds if they are happy, sharp grunts to complain, and screams to threaten or signal danger.

The adult male is called a silverback, because the hair on his back, thighs, neck and shoulders turns silver when he matures after about 13 years.

Gorillas eat almost continually, consuming 30 kilograms of food each day.

Thistles, nettles, wild celery, bamboo, blackberries and other rain forest vegetation make up their vegetarian diet.

The gorillas' survival is threatened by man. Poachers set traps or snares for other animals and gorillas are sometimes accidently caught.

Because gorillas are so closely related to man, they are susceptible to some human ailments, including respiratory diseases, polio and even measles.

Perhaps the greatest threat is habitat loss.

More than half the gorilla habitat in Rwanda has been lost in the past 30 years.

When man can understand the value of these magnificent creatures - as a precious natural resource, as a population for scientific study, as an important part of the rain forest ecosystem - the future of mountain gorillas will become more certain. WWF HK is a local charity environmental organisation established in 1981. Its mission is to build a future in which people can live in harmony with nature. For further information, please call 2526 1011.