These have the biggest population of the gorillas’ species with approximately 2500 individuals. They are common in the Western lowland areas of West and Central Africa in the heavy rain forests of Cameroon, Central African Republic, Equatorial Guinea, Gabon, Angola and some in DRC (Kahuzi Biega National Park).
Lowland Gorillas population trend
The first census conducted in Kahuzi-Biega National Park we have knowledge of is the 1979 survey. This counted 223 gorillas, divided into 14 families and 5 solitary males. Another survey was conducted in 1990 and counted 258 gorillas divided into 25 groups and 9 solitary males. The population was showing a slight increase in the individual gorillas.
In 2004 a census carried out revealed 168 low-land gorillas and this was a slight decrease because of the unending war conflicts with in the country during the Ninetieth. However, due to the increased conservation efforts encouraged by the Wildlife Conservation Society and the Institut Congolais pour la Conservation de la Nature (ICCN) in Kahuzi-Biega National Park in the Democratic Republic of the Congo, the 2010 census showed an increase with the number of gorillas at 181 individuals.
Human disturbance within the bridge zone between highland and lowland forests usually prevents gorillas from making contact with their neighbors and this reduces the possibility of out breeding within the Park and hence a constant population.
Scientific research about the low-land gorillas
Like all gorillas, Eastern Lowland gorillas have a broad chest and shoulders, a large head and a hairy shiny black face. A full-grown male can weigh up to 200kg, and can be distinguished from the Mountain gorilla by its slightly narrower body and face and its noticeably rounder nostrils.
Low gorillas inhabit the tropical forests of Eastern DRC and just like mountain gorillas, Eastern Lowland gorillas suffer terribly from habitat loss, but in some areas this loss is magnified by the illegal mining industry or by the lack of legal protection for the gorilla habitat. These are the only gorillas that can survive in captivity and when there, they display significant intelligence and sometimes learn simple human sign language.
Characterizes and behavior
The lowland gorillas are a bit smaller than the mountain gorillas and have shorter hair and longer arms. Though they climb trees, they are usually found on the ground in communities of up to 30 individuals. The communities are usually organized in accordance to fascinating social structures led by one dominant silverback. Their community is also comprised of juveniles, females and their off springs. The Silverback organizes troop activities such as eating, nestling, moving around and protecting the family in a way that none of the members moves 40 square-kilometers away from home. Young gorillas, from three to six years old, remind human observers of children. Much of their day is spent in play, climbing trees, chasing one another, and swinging from branches.
Those who challenge this alpha male are apt to be cowed by impressive shows of physical power. He may stand upright, throw things, make aggressive charges, and pound his huge chest while barking out powerful hoots or unleashing a frightening roar. Despite these displays and the animals' obvious physical power, gorillas are generally calm and nonaggressive unless they are disturbed.
Female gorillas give birth to one infant after a pregnancy of nearly nine months. Unlike their powerful parents, newborns are tiny-weighing four pounds (two kilograms)-and able only to cling to their mothers' fur. These infants ride on their mothers' backs from the age of four months through the first two or three years of their lives.
The Eastern lowland gorillas have a more diverse diet which varies seasonally. They eat mostly leaves and pith and fruits make up as much as 25% of their diet. All gorillas rarely drink water "because they consume succulent vegetation that is comprised of almost half water as well as morning dew". The lowland gorillas find plenty of food for their vegetarian diet in the thick rain forests and eat roots, fruits, wild celery, tree barks and pulp.
Low land gorillas also mate for reproduction purposes and not for fun. The Females are sexually mature at the age of seven to eight years and cannot reproduce until they are ten years old. All males begin to breed at the age of 12 or 15 years and females give their first birth at the age of 10. Low land gorillas may breed year round and females are in estrus for one to two days per month and only the dominant silverback has breeding rights. Silverbacks are polygamous in nature because the dominant silverback mates with several females in his troop.