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WHAT IS A GORILLA, HOW DO GORILLAS LOOK, GORILLA SCIENTIFIC CLASSIFICATION

What is a Gorilla?If you are asking yourself what is a Gorilla? and how do gorillas look like? Well! Gorillas are massive ground-dwelling apes that live in Central

-east Africa and West African forests. There are several examples of famous gorillas and gorilla stories known by many people around the world.

Gorillas are very common primates in popular culture, and almost anyone will name at least one character, like King Kong, or those in the Planet of the Apes.

In many people’s imagination, gorillas are strong, powerful, and aggressive creatures that pound their chest angry, roar, and show sharp canine teeth, and can rip your head off at the slightest provocation.

In contrast with this stereotype popularized in movies, series, cartoons, and video games, the reality is another, because these primates show peaceful behavior and are among the most amazing creatures on earth.

What are gorillas? In facts gorillas often referred to as peaceful and gentle giants. They possess several human-like behaviors and emotions, such as laughter and sadness.

One of the most interesting Gorilla facts is that they share 98.3% of their DNA with humans, making them our closest cousins after chimpanzees and bonobos.

The largest of the great apes, gorillas are stocky primates with broad chests and shoulders, long human-like hands, small ears, and small eyes set into hairless faces. They have a flat nose with large nostrils. They possess no tails. The color of their eyes is dark brown, framed by a black ring around the iris.

Gorillas live in families like humans. A gorilla family usually consists of several adult females, many juveniles, and Gorilla infants. The head of each family is a dominant adult male known as “Silverback” for the silvery back patches which signal full adulthood. The bond between the silverback and his females forms the basis of gorilla social life.

Origin of the name gorilla: When were gorillas discovered?

Gorillas, the world’s largest living primates have their name derived from Ancient Greek Gorillae ‘tribe of hairy women‘, described by a Carthaginian explorer called Hanno the Navigator around 500 BC.

During an expedition on the West African coast, Hanno met “savage people”, most of whom were women, whose bodies were hairy, and whom his interpreters called Gorillae.”

It is not clear whether what the explorers had seen was what we now call gorillas, another species of apes or primates, or humans.

It is assumed that the skins of gorillae women brought back by Hanno were kept in Carthage until Rome devastated the city 350 years later at the end of the Punic Wars, 146 BC.

Thomas Staughton Savage, the American physician and Jeffries Wyman, a naturalist, first described western gorilla (they called it Troglodytes gorilla) from specimens collected in Liberia in 1847.

Types of gorillas/ Gorilla types

How many types of gorillas are there?  There are two different species of gorillas. Until 2001, gorillas were considered to be a single species (Gorilla gorilla) with 3 subspecies:-

  • The western lowland gorilla
  • The eastern lowland gorilla
  • The mountain gorilla

The western race of gorilla was formally described in 1847 but the mountain gorilla remained unknown to zoologist until 1903 when a Germany army officer Captain Friedrick Robert Von Beringei shot two large apes during an expedition to establish German East Africa boundaries.

One of the apes was recovered and sent to the Berlin Zoological Museum, where Professor Paul Matschie (1861–1926) classified it as a new form of gorilla and named it Gorilla beringei after Friedrick Robert Von Beringei.

Post-millennial advances in DNA testing and fresh morphological studies have forced the revision of this conventional taxonomic classification.  There is now agreement that there are 2 species of gorillas each with 2 subspecies.

Below is a table showing the two species, two sub-species of gorilla and their population sizes.

Species Subspecies Scientific name Population
East gorilla (Gorilla beringei) Mountain gorilla Gorilla beringei beringei 1063
Eastern lowland gorilla Gorilla beringei graueri 3,800
West gorilla (Gorilla gorilla) Western lowland gorilla Gorilla gorilla gorilla 95,000
Cross-river gorilla Gorilla gorilla diehli 250-300

The 2 species and 4 subspecies developed from a single type of gorilla during the Ice Age, when their forest homes diminished and became isolated from each other.

Some variations that distinguish the different types of gorillas include;

  • Varying density
  • Size
  • Hair colour
  • Length
  • Culture
  • Facial widths

The Eastern gorilla is the largest species of gorilla and the mountain race is the most precious of all gorilla subspecies.

The coat of the Eastern gorilla is darker than the western gorilla. Also, mountain gorillas are the darkest of all gorilla subspecies and have the thickest fur. The western lowland gorilla has a reddish forehead and its coat can be brown or greyish.

The eastern gorilla also has a broader chest and a longer face than the western gorilla.

Below is a description of the four gorilla subspecies.

Mountain gorilla: What is a mountain gorilla?

Known scientifically as Gorilla beringei beringei, the mountain gorilla is one of the 2 sub-species of the eastern gorilla (Gorilla beringei).

Although their name implies that they simply live in mountains, mountain gorillas actually prefer forested mountains, living at elevations between 2400 meters and 3900 meters.

Mountain gorilla population

Is estimated at around 1063 individuals. They are the only race of gorillas whose population is increasing.

And from 2008, the International Union for Conservation of Nature (IUCN) which sets the conservation status of species changed the status of mountain gorillas from critically endangered to endangered.

There are two populations of mountain gorillas.

One population of around 604 mountain gorillas is found in the Virunga volcanic mountains of Central-East Africa, within three National Parks:

The other population of about 459 mountain gorilla is found in Bwindi Impenetrable National Park in southwestern Uganda.

There are few natural enemies of mountain gorillas and often live up to 50 years, but long-term survival is critically threatened by poaching, deforestation and exposure to human-borne diseases.

Physical description of mountain gorillas

Mountain gorillas can be distinguished from lowland counterparts by several adaptions to its high-altitude home, most visibly a longer and more luxuriant coat hair.

Mountain gorilla weight: how heavy is a gorilla?

  • The mean weight of a Male mountain gorilla is about 195 kg

  • The mean weight of a female mountain gorillas is about 100kg

It is on average bulkier than other races, (except the Eastern lowland gorilla) with the heaviest on the record being Silverback Guhonda at 220kg, the dominant silverback in Sabinyo gorilla family in Rwanda’s Volcanoes National Park.

What is a Gorilla?

 

Mountain gorilla height:

  • The mean height of males is 5 feet

  • The mean height of females is 4 feet

Fully grown males can reach 6 feet in height with an arm span of 7 feet.

Social behaviors of mountain gorillas

Mountain gorillas are highly sociable living in defined groups/families of 5 to 30 individuals. A gorilla family is called a troop. A group typically consists of;

  • One dominant silverback male (the male’s back turns silver when reaches sexual maturity at about 13 years old).

  • One or more subordinate silverbacks

  • A harem of 3 or 4 mature females, and

  • Several young ones

The dominant silverback organizes the activities of the group including eating, nesting in leaves, and moving about in a home range of about 16 square miles.

Those who try to challenge the dominant silverback are always scared away by an impressive display of physical power by;

  • Barking out powerful hoots or unleashing a frightening roar

  • Standing upright and move bipedally

  • Slapping and tearing vegetation

  • Pounding his chest with cupped hands, and

  • Thumping the ground with palms

Despite these displays and the apparent physical strength, mountain gorillas, are generally calm and non-aggressive.

Mountain gorilla communication

The home of gorillas can be dramatic and very loud when they need to make themselves seen and heard through the dense lush forests.

Hoots, grunts, barks, deep rumbling belches, screams, growls, and roars are all part of their repertoire as well as smaller, subtler sounds and gestures that are just as important for being understood during social interactions.

Mountain gorilla vocalization and verbal communication are associated with different behaviors such as feeding, play, alarm, and anger and can also be used alongside specific gestures and expressions.

Mountain gorilla diet

What do mountain gorillas eat? Mountain gorillas are primarily vegetarians. The diet of gorillas mainly centers on bamboo shoots, but it has been recorded eating leaves, shoots, fruits and other parts of over 142 different plant species.

A male adult mountain gorilla can eat up 34kg of vegetation a day, and a female can consume as much as 18 kilograms.

About 2% of its diet is made up of insects and other invertebrates, with ants being the most favoured protein supplement.

Mountain gorilla locomotion

Gorilla spends most of their waking hours on the ground but can climb fruiting trees for feeding. Mountain gorillas are surprisingly sedentary creatures usually moving not more than 1 kilometer a day, which makes tracking them very easy.What is a Gorilla?

A gorilla will generally move a long distance after a stressful incident, for example, an aggressive encounter with other gorillas, but this quite rare because they are fundamentally peaceful animals.

Mountain gorillas mainly move on fours (quadrupedally). They move by knuckle-walking (like the common chimpanzee, but unlike the bonobo and both orangutan species), supporting its weight on the backs of its curved fingers rather than its palms. They are also capable of moving bipedally (on twos) up to 20 feet.

Mountain gorilla reproduction

Females usually give birth to one infant after a pregnancy of nearly nine months.

Unlike their powerful parents, baby gorillas are tiny—weighing about 1.8 kilogram—and able only to cling to the fur of their mothers. Gorilla infants ride on their mothers’ backs from the age of 4 months through the first 2 or 3 years of their lives.

Young gorillas, from 3 to 6 years, can remind human observers of children. They spend much of their day time playing, chasing one another, climbing trees and swinging from branch to branch.

The scientific study of Mountain gorillas

The first study of mountain gorilla was undertaken in the 1950s by George Schaller in 1950, whose pioneering work formed the starting point for the better publicized research initiated by Diani Fossey in 1960s.

The brutal and still unsolved murder of Fossey at her Rwanda Research Center in 1985 is generally thought to have been the handiwork of one of the many poachers with whom she crossed sword in the Virungas.

Fossey’s acclaimed book, ‘Gorilla in the Mist’ remains perhaps the most accessible starting point for anyone who wants to know more about mountain gorilla behaviour while the eponymous movie, a posthumous of her life attracted the global attention to the plight of mountain gorillas.

Eastern lowland gorilla: What is the Eastern lowland gorilla?

The eastern lowland gorilla is the largest of the four gorilla subspecies weighing up to 250 kilograms. Its scientific name is Gorilla beringei graueri and it is one of the two subspecies of the eastern gorilla. The Eastern lowland gorillas are endemic to mountainous forests of the eastern region of the Democratic Republic of Congo.

Although they are commonly referred to as the Eastern lowland gorillas, their name was changed to Grauer’s gorilla to better reflect the range of habitats in which they are found.

Although most Grauer’s gorillas do live in lowland forests at altitudes as low as 600m, their range extends up to 2900 meters.

Because of the decades of civil unrest in the Democratic Republic of Congo, these areas have historically been difficult to access by researchers, and not much is known about Grauer’s gorillas.

  • Eastern lowland gorilla population

As recently as the mid-1990s, an estimated 17,000 eastern lowland gorilla population remained in the wild, but by 2016, it was thought that the population has dropped to around 3800 individuals largely as a result of civil wars in the Democratic Republic of Congo.

Eastern lowland gorillas are currently classified as critically endangered and are the most rapidly declining of all gorilla subspecies.

Unlike mountain gorillas, which are found in three countries (Democratic Republic of Congo, Rwanda and Uganda) Grauer’s gorillas are found only in the eastern DRC.

Important populations of this gorilla live in;

How do eastern lowland gorillas look like?

Eastern lowland gorillas have a jet black coat like the mountain gorilla, but the hair is shorter on the head and body. Like other gorillas, the coat of the male becomes grey as the animal matures resulting in the designation “silverback”.

  • The average weight of an adult male Eastern lowland gorilla is 210 kilograms
  • The average weight of an adult female Eastern lowland gorilla is 100 kilograms
  • Male’s maximum standing height is 6.1 feet
  • Female’s maximum standing is 5.2 feet

Social behavior of Eastern lowland gorilla

East lowland gorillas are highly sociable and peaceful creatures living in families or groups called troops. Eastern lowland families are usually larger than those of western gorilla, consisting of 2 to 30 individuals.

A group usually consists of 1 silverback, several females, and their offspring.  Silverbacks are powerful and each group has one dominant leader. These males protect their group from danger.

After reaching maturity, young silverback males slowly start leaving their natal group, and will then attempt to attract females to form their own families.

What does eastern lowland gorilla eat?

Eastern lowland gorillas spend long hours feeding on plant matter every day. Their diet includes varied plants diet including;

  • Fruits
  • Leaves
  • Stems
  • Bark
  • And small insects such as ants and termites, insects form only a minor part of their diet.

Why is eastern lowland gorillas critically endangered?

Threats to Eastern lowland gorilla survival include;

Poaching for bushmeat

This is the primary cause of the decline in the Eastern lowland gorilla population. Eastern lowland gorillas are eaten by displaced peoples residing in the region affected by the civil war, militias groups, loggers and miners.

Surveys have shown that great apes, chimpanzees and bonobos comprise 0.5-2% of the meat found in bushmeat markets in the Democratic Republic of Congo.

Civil unrest in the Democratic Republic of Congo

The civil war in the Democratic Republic of the Congo means military groups remain in the forest for long periods of time. Violence in the region has made research on these gorillas difficult and it has become very difficult to protect them.

Thus, poaching has increased as militia and refugees become hungry. Military leaders have also disarmed the park security guards in national parks meaning they have virtually no control over the activities that occur within the park.

Logging, mining, and agriculture

Western lowland gorilla: What is the West lowland gorilla?

The Western lowland gorilla is scientifically known as Gorilla gorilla gorilla and one of the two subspecies of the western gorillas (Gorilla gorilla). They are not only the smallest of the four subspecies of gorillas but also the most numerous and widespread of all gorilla subspecies. About 100,000 western lowland gorillas exist on earth today with around 4,000 in zoos.

In Africa where they live in the wild, inhabiting the montane, primary and secondary forest and lowland swampland of;

What is a Gorilla?

  • Angola
  • Cameroon
  • The Central African Republic
  • Republic of the Congo
  • The Democratic Republic of the Congo
  • Equatorial Guinea, and
  • Gabon

How do western lowland gorillas look like?

Although western lowland gorillas are the smallest of the four subspecies of gorilla, they still have exceptional size and strength.

  • The average weight of an adult male western lowland gorilla is 140 kilograms.

  • The average weight of an adult female western lowland gorilla is 90 kilograms.

  • Adult male western lowland gorillas stand up to 5 feet tall

  • Adult female western lowland gorillas stand up to 4 feet tall

  • A fully grown male can weigh up to 181 kilograms and stand up to 6 feet tall.

The Western lowland gorilla can also be distinguished from other gorilla subspecies by their brown-grey coats, longer arms, auburn chests, and a more prominent ridge along their brow. Their skulls are wider, ears are smaller and their brow ridges are more pronounced.

Infant gorillas possess a tuft of white hair on their backsides, and older gorillas can get streaks of silver in their hair. Western lowland gorilla also has proportionately large hands with nails on all digits, similar to those of humans, and very large thumbs.

They have short muzzles and large nostrils. These gorillas often stand upright, but walk in a hunched, quadrupedal fashion, with hands curled and knuckles touching the ground.

This movement style needs long arms, which works for western gorillas since the arm span of gorillas is larger than their standing height.

  • Social behavior of western lowland gorilla

Western lowland gorillas live in the smallest family groups of all gorillas, with an average of 4 to 8 members in each family.

The head of every family is on dominant male known as a silverback, because of silvery back patches that signal full adulthood. Silverback organizes the family activities including travelling in their home range, feeding, and nesting in leaves.

  • What does western lowland gorilla eat?

As primarily herbivorous, the main diet of western lowland gorilla groups consists of;

  • Roots

  • Shoots

  • Fruit

  • Wild celery

  • Tree bark, and

  • Pulp

During the wet season gorillas commonly consume fruits. And in the dry season, there is a decrease in the consumption of fleshy fruits, though they still continue to eat other kinds of fruits.

Western lowland gorillas also eat insects from time to time.

Cross-river gorilla: What is a cross-river gorilla?

The Cross River gorilla, the rarest great apes in the world, is scientifically known as Gorilla gorilla diehli. It is one of the two subspecies of the western gorillas (Gorilla gorilla) and listed as critically endangered on the IUCN red-list.

Their population in the wild is estimated at around 250-300 individuals and only one gorilla is known to exist in captivity.

Cross-river gorillas are restricted to the mountainous border area between Cameroon and Nigeria at the top of the Cross River, after which they are named.

They are rarely seen, mostly captured on camera traps and are thought to be extremely wary of humans following a long history of persecution. Cross-river gorilla often resides in the deepest, most inaccessible pockets of terrain.

  • How do cross-river gorillas look like?

First described as a new subspecies of the western gorilla in 1904 by Paul Matschie, the Cross River gorilla’s morphological distinctiveness was confirmed in 1987.

When comparing the Cross River gorilla to western lowland gorillas, they have noticeably smaller palates, smaller cranial vaults, and shorter skulls.

The Cross River gorilla is not known to differ much in terms of body size or limb and bone length from western lowland gorillas.

However, measurements taken from a male suggest that they have shorter hands and feet and have a larger opposability index than western lowland gorillas.

Size of the cross-river gorilla (height and weight)

  • The average height of an adult male Cross River gorilla: 5 feet

  • The average weight of an adult male Cross River gorilla: 140–200 kilogram

  • The average height of an adult female Cross River gorilla: 4 feet

  • The average weight of an adult female Cross River gorilla: 100 kilogram

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