Gorillas are believed to be ground-dwelling, predominantly herbivorous apes that inhabit the forests of central Africa.
They are divided into two species; the eastern gorillas and the western gorillas.
They are the largest living primates believed to be having their DNA highly similar to that of humans.
They are the next closest living relatives to humans after the chimpanzees and bonobos.
Their natural habitats cover tropical or subtropical forests in Africa. Although their range covers a small percentage of Africa.
Gorillas cover a wide range of elevations, the mountain gorilla inhabiting the Albertine Rift montane cloud forests of the Virunga Volcanoes.
It is also on record that the lowland gorillas live in dense forests and lowland swamps and marshes as low as sea level.
The western lowland gorillas are found to be inhabiting most parts of Central West African countries.
Whereas the eastern lowland gorillas live in the Democratic Republic of the Congo near its border with Rwanda.
Historically, the word “gorilla” comes from the history of Hanno the Navigator, a Carthaginian explorer on an expedition on the west African coast to the area.
Members of the expedition encountered a savage people, the greater part of whom were women, whose bodies were hairy.
It is also recorded that, closest relatives of gorillas are the other two Homininae species i.e. chimpanzees and humans.
That they are believed to have diverged from a common ancestor about 7 million years ago. Human gene sequences differ only 1.6% on average from the sequences of corresponding gorilla genes.
However, there is a further difference in how many copies each gene has. Gorillas were considered to be a single species, with three subspecies: the western lowland gorilla, the eastern lowland gorilla and the mountain gorilla.
It can now be understood clearly that, there are two species, each with two subspecies. More recently, a third subspecies has been claimed to exist in one of the species.
The separate species and subspecies developed from a single type of gorilla during the Ice Age, when their forest habitats shrank and became isolated from each other in most of the areas they inhbited.
The proposed famous third subspecies of Gorilla beringei, is the Bwindi population of the mountain gorilla, sometimes called the Bwindi gorilla
Generally, their classification varies in density, size, hair colour, length, culture, and facial widths.
They move around by knuckle-walking, although they sometimes walk bi-pedally for short distances while carrying food or in defensive situations.
Male gorillas weigh 135 to 180 kg while adult females usually weigh half as much as adult males at 70–115 kg.
Adult males can be seen to be around 1.7 to 1.8 m tall, with an arm span that stretches from 2.3 to 2.6 m.
Female gorillas are shorter, with smaller arm spans. Adult male gorillas are known as silverbacks due to the characteristic silver hair on their backs reaching to the hips.
The eastern gorilla is more darkly colored than the western gorilla, with the mountain gorilla being the darkest of all.
The mountain gorilla also has the thickest hair whereas the western lowland gorilla can be brown or grayish with a reddish forehead.
Gorillas that live in lowland forests are seen to be more slender and agile than the more bulky mountain gorillas.
Nesting of Gorillas
Gorilla night nest can be seen constructed in a tree. Nests tend to be simple aggregations of branches and leaves about 2 to 5 ft in diameter.
Gorillas tend to sleep in nests on the ground. And the young nest with their mothers, but construct nests after three years of age.
Gorilla nests are distributed arbitrarily and use of tree species for site and construction appears to be opportunistic. Nest-building by great apes is now considered to be not just animal architecture, but as an important instance of tool use.
Mountain gorilla family. Gorillas are seen living in groups called troops with one adult male or silverback, multiple adult females and their offspring.
Also, multiple-male troops also exist. A silverback is typically more than 12 years of age, and is named for the distinctive patch of silver hair on his back, which comes with maturity.
It is also noted that, mature males also tend to leave their groups and establish their own troops by attracting emigrating females.
For male mountain gorillas, sometimes they stay in their natal troops and become subordinate to the silverback.
Conclusively, the gorilla’s lifespan is normally between 35 to 40 years, although zoo gorillas may live for 50 years or more.