Hidden cameras show gorillas going ape

A western lowland gorilla under a blanket. (supplied)

Hidden cameras are revealing what Werribee Open Range Zoo’s family of Western lowland silverbacks get up when they think no one is watching.

The gorillas are seen expressing their instinctive playful, curious and territorial behaviours in unusual ways, from making grass ‘angels’ to playing tug-of-war with a branch.

Werribee Open Range Zoo gorilla keeper Kieralie Braasch said these actions show that 39-year-old Motaba and his two 23-year-old sons Yakini and Ganyeka, are comfortable within their island home.

“Ganyeka makes angel shapes in the grass most likely because the grass is wet and he likes the feeling of it on his skin,” Ms Braasch said.

“The chest-beating we see is normally a territorial behaviour, but in this case it’s a playful practice.”

In one of the scenes revealed by camouflaged cameras, Ganyeka hides from the rain using a plant-fibre blanket placed on his back.

Ms Braasch said that gorillas often dislike the rain, and Ganyeka is no different.

“Sheltering with available materials is a behaviour we see Ganyeka doing quite often when he goes out to forage while it’s raining,” Ms Braasch said.

“He either hides under the blanket or stays undercover.”

As for play fighting over a branch, that is important instinctive behaviour among a gorilla troop.

“Yakini and Ganyeka occasionally engage in brotherly tug-of war, which is a playful way to exercise their strength and territorial instincts,” Ms Braasch said.

The gorilla troop’s quirky antics are common behaviours, so visitors may be lucky enough to see them go ape in person.

Western Lowland Gorillas are one of four gorilla sub-species, and are classified as Critically Endangered by the International Union for Conservation of Nature (IUCN). Wild populations are threatened by habitat loss from logging and the impact of mining for coltan, a mineral used to make mobile phones.

Zoos Victoria’s ‘They’re Calling On You’ initiative encourages the public to donate unwanted mobile phones that can be recycled to raise funds for wild gorilla care and conservation. Visitors to Werribee Open Range

Zoo can drop off their old mobile phones and accessories into the specially marked collection bins located inside the zoos’ entrance.