Why You Need to See Africa’s Mountain Gorillas in Uganda

How much does a gorilla weigh?
Gorillas are the world’s largest primates, with males weighing around 200kg and standing about 1.4-1.8m tall in the wild. Females tend to be 20-30cm shorter and weigh roughly half what the males do.

A male gorilla’s armspan is enormous, stretching 2.3-2.6m, while female gorilla’s armspans are proportionally smaller.

It’s hard to measure how strong a gorilla really is, but estimates range from around 4x – 10x stronger than your average human. A silverback gorilla’s strength is certainly formidable. All gorillas can tear down banana trees without trying too hard, they’ve escaped from cages by bending the iron bars, and they have a bite force of around 1300 psi, double that of a lion.

Aggressive gorilla baring its teeth
But apart from in conflicts between silverbacks, gorillas tend to be gentle giants that rarely display their full strength. They’re also built quite differently to humans, which makes them more efficient climbers and better adapted to walking on all fours.

That means that measuring their strength by human standards doesn’t make a huge amount of sense, as they wouldn’t be able to perform some of the movements we take for granted because they balance completely differently.

How clever are gorillas?
Gorillas are highly intelligent. They don’t use tools as much as chimpanzees do, but wild gorillas have been seen using sticks to gauge water depth, bamboo as ladders to help infants climb, and recently gorillas have been seen for the first time using sticks to eat ants without being stung.

Another sign of intelligence is the gorilla’s impressive communication abilities, and they’ve been recorded making some 25 different sounds.

What do gorillas eat?
Gorillas are mainly herbivores, and their diet mostly consists of bamboo, fruit and leafy plants, though western lowland gorillas also eat small insects. Adult gorillas can eat up to 30kg of food each day.

As roaming herbivores, gorillas play a vital role in seed dispersal. Many large fruit trees depend upon these animals to survive.

Research published in early 2016 showed that gorillas hum when contentedly when eating their favourite food.
“Gorillas seem to hum and sing when encountering food they really like,” explained Simone Pika of the Max Planck Institute for Ornithology, who led the study.
“This is very similar to our own behaviour when eating delicious food and emphasising this by also making ‘mmmmm’ sounds.”

How long does a gorilla live?
In the wild, a gorilla’s lifespan is around 35-40 years, but they often live longer in captivity, sometimes for over 50 years. The oldest gorilla ever recorded was a female western gorilla at the Columbus Zoo that reached the ripe old age of 60 before dying in 2017.
Gorillas are classed as infants until they reach around three-and-a-half years old, and adults from around 8 years. Males between 8-12 years are called ‘blackbacks’. Then from 12 years old, they develop a silver section of hair over their back and hips, earning them the name ‘silverback’.

Where do gorillas sleep?
Gorillas build nests in which to sleep, both on the ground and in trees, made of leaves and branches. Counting abandoned nests is an effective way for scientists to estimate population size.

All great ape species, including humans, like to rest in a comfortable place at night. Just how humans like to curl up in a bed with blankets, gorillas, orangutans, chimpanzees and bonobos all find materials in their environment to use as bedding! In fact, humans are the only great ape that doesn’t build a new nest every night. While mountain gorillas nest almost exclusively on the ground, the other types of gorillas as well as other great apes generally make their nests high in the treetops and off the ground from potential predators.

Gorillas usually start making their nests about an hour before the sun sets, in time to be in bed by dark! They typically stay in their nest the entire night, just like people. However, gorillas sleep longer than humans, averaging about 12 hours of rest each night.

How can you tell individual gorillas apart?
Just like us, humans have unique fingerprints, but that’s not much use for identification in the field.

More helpfully, gorillas also have unique noseprints, which can be used to identify individuals from photographs by looking at the nostrils and the bridge of the nose.

How can gorillas knuckle-walk?
Gorillas (plus chimps and bonobos) are specialised knuckle-walkers. This is not because they can’t carry their weight upright – they can walk bipedally when necessary. As knuckle-walkers, gorillas have various adaptations for stability and weight-bearing.

The middle and end phalanges (finger bones), which bear the animal’s weight, are widened and flattened for extra strength; in the forearm, the end of the radius that sits nearest the hand is both cupped and downward-facing, allowing it to fit snugly beside the scaphoid in the wrist; the metacarpals (knuckle bones) have ridges that ‘lock’ into place with the phalanges; and the skin on the fingers is thick as well as heavily padded.

How many babies do gorillas have?
Females usually produce just one baby every four to six years. In total, a female will only give birth three or four times. Such a low reproduction rate makes it difficult for populations to bounce back following a decline.

A study in 2012 on captive populations revealed that female western lowland gorillas use a type of ‘baby talk’ to communicate with their babies. Scientists observed that mothers used more tactile and more repetitive gestures with their young than with other adults.

Where do gorillas get their name from?
The history of the word ‘gorilla’ stretches back at least 2500 years. A Carthaginian explorer named Hanno the Navigator was on an expedition to the African west coast in around 500 BC when he came across a group of predominantly female primates that he described as savage, hairy women. We can’t be certain whether these were actually gorillas, some other kind of ape or even an unknown group of people, but Hanno’s interpreters told him they were called ‘gorillae’ and the name stuck.