The Western Lowland Gorilla, where the male is often referred to as the Silverback, is among my favorite animal to observe and photograph. Belonging to the family "Pongidae" or the "Great Apes" these amazing creatures exhibit strength and intelligence which can be seen in the interactions they have with each other, their interactions in navigating their habitat, their facial expressions, and body movements. Calculated, thoughtful, compassionate, protective, nurturing, and surprisingly peaceful, unless provoked, are adjectives I would use to describe them having observed and photographed them for over the years.
The Western Lowland Gorilla is the largest of all the primates. They have distinguishing features such as large heads, small ears, pronounced brow ridges, muscular necks, broad shoulders, long arms, strong hands and feet. The average Western Lowland Gorilla stands 4-6 feet high and can weight anywhere between 150 to 400 pounds.
Like many animals, the Western Lowland Gorilla's live in communities or troops of 30 individuals. These communities or troops then split off into small families of 4-8 members with typically a dominate, mature, single male gorilla who protects the family structure of several unrelated female gorillas and infants. The gorillas are social creatures and depend on each other to survive. The strongest bond forged in the family is formed between the dominant male and his female. That bond, as you will read, is essential in the reproduction in his community. The Silverback, as leader of his family, regulates the schedule of his family for eating and nesting. The home range, they travel within, can be anywhere between 3/4 to 16 miles. Most will spend several hours throughout the morning eating. Midday, the Western Lowland Gorillas can be found taking a break with the adults napping and the youngsters playing. The family will return to eating again, before nightfall, and then will nest and sleep for the night. Western Lowland Gorillas have been found to make up to 25 different vocalizations, with each having it's own meaning for grunts, hoots, barks, laughs, and screams as they communicate with each other.
Competing Gorilla Groups
Because Western Lowland Gorillas are shy, peaceful, non-aggressive animals there typically is no conflict between other Silverbacks and their families that have overlapping territories. In cases, were the male gorilla is threatened, he will do everything possible to scare off the trespasser or predator. He will put on an elaborate display of chest beating, running sideways, vocalizations, and even tearing up vegetation to show his dominance and scare off a trespasser or other male. Female gorillas allow the head male gorilla to handle the situation and only become aggressive if and when they are defending their infants. Every once in awhile they become aggressive while helping each others deal with rowdy, young, adult male gorillas. If needed, when squabbles begin, the Silverback will step in as the peacekeeper and intervene to calm the situation down.
Life Cycle & Babies
Western Lowland Gorillas live approximately 30 to 40 years in the wild; and, 40 to 60 years in captivity. While normally quiet animals, during mating time gorillas can be quite loud. Western Lowland Gorillas mate less often in comparison to other great apes. Only the dominate male, the Silverback, is allowed to mate with the adult females in his group. The reproductive success of males depends upon the relationship and permanent bond he forms with the females in his family. The formation of the permanent bond with the females keeps the females from leaving the group or even mating with another male. When a baby gorilla is born into the family, at about 9 or 10 weeks of age, the baby gorilla will begin to crawl and then soon begin to walk on all four limbs. At about the same time the baby gorilla begins to walk, a white patch appears on the baby's bottom which helps the mother gorilla keep track of the baby and assist other group members in identifying the gorilla as a baby or infant. The white patch on the baby's bottom begins to disappear approximately at about 3 years of age, about they time they are being weaned. When a male is born into the family, he will remain with his family until approximately 12 years of age and then he will begin to go off and try and attract other females from other groups to form his own group. Females will remain with their family until about the age of 8 or 9 years of age, and then they will join an unrelated solitary male to form an unrelated group.
Habitat & Diet
The Western Lowland Gorillas can be found living in tropical rainforests spread throughout six countries across west equatorial Africa including Cameroon, Central African Republic, Congo and Equatorial Guinea, Gabon, and Southeast Nigeria. A gorillas diet consists mainly of fruits, leaves, and stems. Approximately 67% of their diet is fruit and 17% is seeds, leaves, stems, and pulp. Gorillas prefer the sweeter sugary fruits and pulp. Their diet is rounded out with additional items such as insect larvae, caterpillars and termites. During the wet, rainy season, more fruits are consumed. During the dry season, more leaves and bark is consumed. Female gorillas will stay higher in the trees and eat more leaves than the males. During the wet season males will go out further in search of fruit and spend more time on the ground eating leaves than during the dry season.
The Western Lowland Gorilla is listed on the critically endangered species list. Man is the primary known enemy of these magnificent creatures with the Ebola virus, coming in second, killing one-third of the total wild population. Man has been responsible for the degradation of the tropical rainforest, illegally hunting gorillas for bushmeat, big game hunting, trapping and selling live young gorillas to zoos and research institutions, and provoking them, while peaceful animals, to the point of defending themselves or their families and then they are shot and killed because they are deemed aggressive. The combination of man and the Ebola virus is proving to be be a deadly combination that has numbers dwindled rapidly down, with some reports showing population decline in eight years by 20%, has led to them being placed on the critically endangered species list. While still listed as critically endangered, exact number counts have been inconsistent and new research, as of the writing of this blog, indicates that possibly gorilla (and chimpanzee) numbers may be higher than once thought in the African area; however, the population that was found is in an unprotected area. One can only hope the numbers are more accurate and better protection can be put in place for them to sustain and grow the population otherwise, the Western Lowland Gorillas last chance for survival may very will be the few gorilla sanctuaries in Africa, zoos, and other captive environments throughout the world.