Fast Fact Attack: Endangered Species No. 81 – The Eastern Lowland (Grauer’s) Gorilla


Grauer's Gorilla (Gorilla beringei graueri)

“The worst sin toward our fellow creatures is not to hate them, but to be indifferent to them; that’s the essence of humanity”
George Bernard Shaw

During the conflict in the Democratic Republic of the Congo, the people were not the only ones to suffer.  Populations of gorillas were depleted dramatically.  This highly biodiverse country is among the poorest in the world and this species was, and still is, greatly exploited as a food source.  Mothers have been slain and babies sold on the black market, and parts of the animals have been traded for medicinal usage.  The species can currently be found in an area where refugees, poachers and militia still abound.Kijivu, a captive lowland gorilla, feeds her one-day-old infant, at a zoo in Prague, Czech Republic, Sunday. Kijivu gave birth to the baby Photo Michal Dolezal

The Eastern lowland gorilla, also known as Grauer’s gorilla, is the largest of all the gorilla species and one of the five great apes; in the company of orangutans, chimpanzees, bonobos and man.  It is one of two sub-species of eastern gorilla found in Africa.  The other is the critically endangered mountain gorilla. The eastern lowland gorilla is far more numerous than the mountain gorilla, but none-the-less, still endangered.

Having heavy bodies, large hands equipped with opposable thumbs, short muzzles and dark-grey to black coats, this species is well-adapted to jungle life.  The backs of the male gorillas, upon reaching maturity, will change to a silvery-white colour, giving rise to the name ‘silverback’.  Faces are hairless, as are hands, ears and feet.  As the animals reaches maturity, the chest will lose hair, too.

Fully grown male Eastern lowland gorillas can weigh up to four hundred pounds and reach a height of five and a half feet when upright.  There is one documented case of a silverback reaching five feet eleven inches – but this is rare.

Gorillas are diurnal and do most of their foraging early morning and late in the day.  The rest of their time is spent sleeping, playing and socially grooming.  Gorillas build, sleep and birth in nests in the trees.  They live in groups of thirty-five to fifty individuals, with the most dominant silverback at the head of the group.

Silverback screamingGorillas, like other primates, have various means of communicating with each other and intruders.  In the case of unwanted callers, males defend their territory, females and babies with a combination of sheer bulk and flamboyant displays of charging and chest beating.  Barks, hoots, roars and screams complete this intimidating package.  Visual gestures, body language and facial expressions are also forms of communication.

Gorillas are polygynous.  There is no set breeding season and the dominant silverback will father most of the offspring.  After a gestation period of about eight and a half months, one  infant will be born (very occasionally two).  Infants weigh roughly four and a half pounds.  Newborns can crawl after nine weeks and walk at eight to nine months. They will nurse for three years or more, remaining in the mother’s nest.  Full maturity comes at about twelve years of age.  Females give birth only once every three or four years.  Unfortunately, there is a very high infant mortality rate.  This greatly affects the Eastern lowland gorilla’s ability to replenish its numbers.

Habitat
Montane, transitional and lowland tropical forests.
Where
Democratic Republic of the Congo.
What they eat
Plants, leaves, stems and bark, fruits and seeds.  They also occasionally consume ants and termites.
Threats
Loss of habitat due to agricultural expansion, degradation of habitat from illegal logging, illegal mining and road building for the same, and charcoal production.  Poaching for bushmeat and medicine, and the capture and trade of baby gorillas has had a detrimental affect on the population, due to the slow reproductive rates of this already diminishing species.   Disease; epidemics such as ebola and diseases passed on by humans are also a large threat.
Status: Endangered
The Eastern lowland gorilla (Gorilla beringei graueri) is listed on the IUCN Red List of Threatened Species as Endangered.
The IUCN has come together with various other well-known international organisations to stave off the extinction of this wonderful primate (see related articles below).  Here is what the IUCN have to say:
“Today, the remaining Grauer’s Gorilla populations are small and localised and occur in regions of intense illegal mining activity and insecurity,” said Stuart Nixon of Fauna & Flora International. “Until we can complete the much-needed surveys, our best guess is that between 2,000 and 10,000 gorillas remain in 14 isolated populations. Without a dedicated effort, the next 10 years will be marked by continuing local extinctions of this forgotten gorilla” (see related articles below).
Other organisations, such as WildLife Direct (also see related articles below), have their own worthy conservation programs for the gorillas.

Baby Eastern lowland gorilla resued from poachers - Virunga Gorilla Park 2011 by LuAnne CaddRelated Articles
Pride: a secret weapon in protecting primates 
Grauer’s Gorilla caught in the crossfire of conflict (IUCN) 
WildLife Direct-  Keeping our gorillas safe and healthy!
Rarest gorillas lose half their habitat in 20 years
Gorillas in the Mist…
Human virus linked to mountain gorilla deaths

Sir David Attenborough launches crowdfunding campaign to save mountain gorillas

Fast Fact Attack – Endangered Species 13: The Western Lowland Gorilla


Western lowland gorilla

Description
Every night, western lowland gorillas build a fresh, leafy nest in which they snuggle down and sleep for about 13 hours. When not sleeping, they are either seeking food or eating it. As gorillas go, they are smaller than their mountain cousins and have shorter hair and longer arms. Despite their huge canine teeth and notably powerful limbs, western lowlands are rarely aggressive. In fact, they are quite gentle. They live in groups led by a dominant ‘silverback’ male. Females give birth after an eight to nine month gestation period, their newborns being surprisingly tiny and weighing in at only about four pounds. The babies learn to crawl at two months and can walk before they are nine months. They ride on their mothers’ backs for the first two or three years of their lives. Gorillas, sadly, have a high infant mortality rate; only half the infants reach maturity. 
Habitat
Lowland tropical forests and swamp forests
Where
West and Central Africa
What they eat
Fruit, leaves, shoots, vines and other such vegetation, and bark; with the occasional termite thrown in for good measure
Threats
Major concerns are the Ebola virus, commercial hunting and hunting by locals for bushmeat.  Habitat destruction is becoming another large factor.
Status: Critically Endangered
Due to such a dramatic decline in numbers (60% over the last 20 to 25 years), attributed mainly to poaching and disease, scientists estimate it will take up to 75 years to fully re-establish the population.

“The worst sin toward our fellow creatures is not to hate them, but to be indifferent to them; that’s the essence of humanity.” George Bernard Shaw