Gorilla: Profile and Information

Gorillas are ground-dwelling, herbivorous apes occupying central Sub-Saharan Africa’s wilderness.

The genus Gorilla can be divided into two species: Eastern gorillas and Western gorillas.

They are the largest living primates, and both species are in danger of extinction.

The DNA of gorillas is highly comparable to that of humans, having a comparison rate of  95% – 99% relative to what is involved.

They are the closest inhabiting relatives to humans after the bonobos and chimpanzees.

The natural homes of gorillas cover the tropical and subtropical forests in Sub-Saharan Africa.

Although their range surrounds a small proportion of Sub-Saharan Africa, gorillas cover many elevations.

The mountain gorilla occupies the Albertine Rift montane cloud forests of the Virunga Volcanoes, reaching an altitude between 2,200 & 4,300 meters.

Lowland gorillas inhabit dense forests and the lowland marshes, which are at sea level.

The western lowland gorillas live in Central West African countries, and eastern lowland gorillas reside in the Democratic Republic of the Congo close to its border with Rwanda.

Scientific Classification

Physical Features of Gorillas

Gorillas walk around with their knuckle and sometimes move like humans when carrying food or in protective situations. Few mountain gorillas use different parts of their hand to support their movement. There is a unique difference in the regularity and comfort with which gorillas walk upright.

Studies have shown that distinctive gorillas at the London and Philadelphia Zoo have been detected walking straight more often and for extended periods than usual. A gorilla at the Philadelphia Zoo, Louis, has been observed to do this to avoid getting dirt on his hands.

Adult male gorillas body weighs between 136 – 227 kg (300 – 500 lb) and a height between 1.4 – 1.8 m (4 ft 7 in – 5 ft 11 in). They also possess an arms-length that extends from 2.3 – 2.6 m (7 ft 7 in – 8 ft 6 in). Adult male gorillas are also called silverbacks because of the distinctive silver hair on their backs, reaching to their hips.

Adult females weigh between 68 – 113 kg (150 – 250 lb), and they have a height of 1.25 – 1.5 m (4 ft 1 in – 4 ft 11 in), with smaller arm size. The eastern gorilla is darker in color than the western gorilla, with the mountain gorilla being the shadiest of them all. The mountain gorilla is also known to have the thickest hair, while the western lowland gorilla has a greyish or brown color with a reddish forehead.

Also, gorillas that dwell in lowland forests are slimmer and more active than the massive mountain gorillas. The eastern gorilla also possesses an extended face and broader chest than the western gorilla.

Research has demonstrated that gorilla blood doesn’t react to anti-A and anti-B monoclonal antibodies, unlike humans, which indicate a type O blood. According to novel sequences, it is distinct enough that it doesn’t correspond with the human ABO blood group structure. However, other giant apes fit into this category.

Like humans,  gorillas have unique fingerprints, and their eye color is grey-brown; a black ring around the iris frames it. The lifespan of a gorilla is generally between 35 and 40 years, although zoo gorillas could live for over 50 years.

A female gorilla at the Columbus Zoo & Aquarium,  named Colo, was the oldest recognized gorilla. She passed on the 17th of January 2017 at the age of  60 years.

Habitats and Distribution

Gorillas have an irregular distribution. The Congo River and its tributaries separate the range of the two species of gorilla. The eastern gorilla dwells in east-central Africa, while the western gorilla inhabits west-central Africa.

Gorilla natural surroundings range from Montane forest to swampland. Eastern gorillas reside in montane and submontane forests between 650 – 4,000 m (2,130 – 13,120 ft) above water level.

Gorillas build nests for day and nighttime use. Nests are the natural accumulations of branches and leaves, about 2 – 5 ft (0.61 – 1.52 m) in diameter. Gorillas are more inclined to rest in nests on the ground than chimpanzees.

The young nest with their mothers but build their nests after three years old.

Diet and Scavenging

A gorilla’s day is divided into resting and feeding or travel periods. The food they consume varies between and within the species.

Mountain gorillas mainly eat vegetation, such as leaves, piths, stems, and shoots, while fruit consumption is a tiny part of their sustenance. Mountain gorilla food is extensively dispersed, and neither groups nor individuals need to compete with one another.

Eastern lowland gorillas have different diets, which range seasonally. Piths and leaves are generally eaten, but fruits comprise about 25% of their diet. They also consume insects, preferably ants.

Western lowland gorillas live on fruits more than the others, and they are more scattered across their range.  They have limited access to terrestrial plants, but western lowland gorillas have access to aquatic herbs in some regions. Western lowland gorillas also consume ants and termites.

Gorillas hardly drink water because they eat juicy foliage comprising almost half water and morning dew. However, both mountain and lowland gorillas have been seen drinking water.

Behavior

Social Pattern

Gorillas living in groups are called troops. Troops are generally made of a single adult male or silverback, numerous adult females, and their offspring. However, multiple male troops can also exist.

Mature male gorillas tend to vacate their groups and create troops by luring migrating females. Nevertheless, male mountain gorillas occasionally remain in their birth troops and become subject to the silverback.

If the silverback departs, these males may be eligible to become prominent or mate with the females. Nevertheless, this behavior has not been seen in eastern lowland gorillas.

When the silverback dies in an individual male group, the female gorillas and their offspring distribute to find a new troop. Without a silverback to defend them, the newborns are likely to fall victim to infanticide.

Competition

One apparent predator of gorillas is the leopard. Gorilla remnants have been discovered in leopard feces, which might result from foraging.

When the troop is ambushed by leopards, humans, or other gorillas, a single silverback will defend the group, even at the expense of its life.

Reproduction and Copulation

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Female gorillas mature at 10–12 years, and the males at 11–13. A female’s initial ovulatory cycle starts when she is six years of age and is accompanied by two years of young infertility. The estrous process persists for about 30 – 33 days, with external ovulation cues related to those of chimpanzees.

The gestation duration lasts for about 8.5 months. Female mountain gorillas give birth to their first offspring at the age of 10 years and have four-year interbirth spans. Male mountain gorillas can be fertile before attaining adulthood. Gorillas mate all year round.

Females will press together their lips and gradually move toward a male while making eye contact. This serves to encourage the male to mount her. If the male does not react, she will attempt to draw his attention by moving towards him or banging the ground.

In multiple-male factions, solicitation suggests a female choice, although female gorillas can be compelled to mate with many males. Males incite intercourse by moving toward a female, caressing her, and giving a train grunt.

Lately, gorillas have been seen directly facing themselves during sex. It is a trait once deemed unique to bonobos and humans.

Communication

Twenty-five diverse vocalizations are acknowledged and utilized mainly for group interactions within dense vegetation. Sounds categorized as barks and grunts are often heard while traveling to know the location of individual troop members. They could also be employed in social interactions when discipline is needed. 

Screams and roars signal alarm and are generated most frequently by silverbacks. Deep beaches and rumbling sounds suggest satisfaction. These are often heard during foraging and sleeping periods.

Conflicts are settled continuously by displays and other dangerous behaviors aimed at intimidating without becoming physical. The formal charge display is personal to gorillas.

The entire process includes nine steps:

• Progressively accelerating hooting
• Symbolic feeding
• Increasing bipedally
• Tossing vegetation
• Chest-beating with cupped hands
• One leg kick
• Sideways running, two-legged to four-legged
• Slamming and ripping vegetation
• Banging the ground with palms to end display

Since gorillas got the attention of Western society in the 1860s, they have been a recurring factor in various aspects of prominent tribes and media. For instance, gorillas have starred in monstrous fiction movies like King Kong and George of the Jungle.

Also, pulp fantasy tales such as Tarzan and Conan the Barbarian have featured gorillas as physical adversaries of the formal heroes.