(Story and Facts by Discover Wildlife)
1 East vs west
There are two species of gorilla – eastern and western. Each of these is divided into two subspecies – eastern lowland and mountain (eastern) and western lowland and cross river (western). The two species live in central Africa, separated by a vast swathe of rainforest.
2 Number crunching
The western lowland gorilla is the most numerous of the four subspecies, with population estimates often cited at 100,000-200,000. However, due to its dense, remote habitat, no one knows for sure how many exist. The least numerous is the cross river gorilla, which is confined to scattered areas of forest in Nigeria and Cameroon, and is thought to number no more than 300 individuals.
3 Size matters
Gorillas are the world’s largest primates. They are closely related to humans, with 98% of their DNA identical to that of Homo sapiens.
4 Seeds of survival
As roaming herbivores, gorillas play a vital role in seed dispersal. Many large fruit trees depend upon these animals to survive.
5 Able apes
Gorillas are highly intelligent. They use tools and have various methods of communication, including some 25 different sounds. One famous captive-born individual, Koko, has been taught sign language since she was a year old. By the age of 40, she had a library of about 1,000 signs and could understand some 2,000 words of English.
6 Food factors
Gorillas are mainly herbivores. They spend most of their day foraging for bamboo, fruit and leafy plants, though western lowlands also eat small insects. Adult gorillas can eat up to 30kg of food each day.
7 Nesting instincts
Gorillas build nests in which to sleep, both on the ground and in trees, made of leaves and branches. Counting abandoned nests is an effective way for scientists to estimate population size.
8 Nose knows
Gorillas have unique noseprints, much like human fingerprints, which can be used to identify individuals.
9 Precious progeny
Females usually produce just one baby every four to six years. In total, a female will only give birth three or four times. Such a low reproduction rate makes it difficult for populations to bounce back following a decline.
10 Chatter matters
A study in 2012 on captive populations revealed that female western lowland gorillas use a type of ‘baby talk’ to communicate with their babies. Scientists observed that mothers used more tactile and more repetitive gestures with their young than with other adults.