Gorillas live in groups consisting of about 25 to 35 members. Usually there is one leading male, accompanied by several females with their young
When a baby gorilla is born it weighs on average 2.5 kg, which is about half the weight of a human baby. However, this baby develops twice as fast. Within 40 weeks it can walk and reaching three years it slowly becomes independent. At six years they are about 1.20 meter tall and weigh almost 70 kg. At this age the female gorilla matures, though they continue gaining weight for the next four years. Males on the other hand do not reach maturity till they are ten years old. When their black back starts turning into grey it is time for them to leave the parental group. They wander alone or join other males for some time, before attracting females who will join them. In this way they form their own family.
Gorillas reproduce slowly, hence the world population doesn’t increase rapidly. Gestation period is approximately 8.5 months and gorilla mothers give birth to a baby once every four years. Unfortunately at least 30% does not survive their first year because of diseases and accidents. Another situation that causes death among the baby gorillas is when their father dies and another silverback takes over. This new male often kills all the babies of his predecessor, securing his own genes in the posterity.
Hierarchy is clear and important within the gorilla family. The dominant silverback enjoys the highest rank and the adult females rule over the younger ones. Like with other species in the animal world, gorilla males achieve the high ranking because of their size. Male mountain gorillas can weigh up to 200 kg and can reach 1.70 meter when they are standing upright. Besides the strength they also have to prove their experience and abilities. It is their duty to protect their family from danger and intruders
It is not difficult to figure out where the name silverback comes from. Around the age of twelve years, they develop light grey hair on their back, giving them a ‘silver back
A DAY IN A LIFETIME OF A GORILLA
An ordinary day in the life of a mountain gorilla starts at sunrise, around 6 am. They wake up and begin looking for food which covers a great part of the morning. In general, a gorilla spends about 30% of the day with feeding, 30% with travelling and 40% with resting. In contrast to many primates, the gorilla lives mainly on the ground. They travel not more than a kilometer per day within their home range of about 20 square kilometers.
Gorillas are vegetarians, though occasionally they may eat ants and other insects. Their daily meal consists of roots, leaves, stems and pith of herbs, vines and shrub, and some fruits. During certain months of the year bamboo shoots supply a major part in their diet as well. A male adult can even eat up to 20 kg per day! Because the gorillas receive a large quantity of water from its diet, they rarely have to drink.
The afternoons are mainly spent with resting and playing. This last activity is very important in the social life, especially for young gorillas, as it determines their integration into the group. They hug each other, bite, hit or wrestle till one is pulled down on the ground.
At the end of the day, just before dusk, the great apes start constructing a nest where they will spend their night. Every single gorilla has its own nest, except for the infants who sleep next to their mothers. Nests are built on the ground or in trees and are carefully constructed by branches of bushes and other plants