18/08/2021

Bristol Zoo Gardens’ surrogate-raised gorilla turns one

Twelve months have passed since a tiny Critically Endangered gorilla was born here at Bristol Zoo Gardens – and his keepers say he’s thriving.

Hasani, the young western lowland gorilla who arrived during the early hours of 19 August last year, is developing at the same rate as a human infant, has around 10 teeth and drinks four bottles of milk a day.

He was born to mum Kala and father Jock – our silverback – but a lack of confidence shown by his mother following the birth led to her refusing to care for him.

It was decided Hasani would be hand-reared by his dedicated keepers who took it in turns to look after him, both day and night.

During his first five months of life, keepers ensured he had sight of the six other gorillas here at Bristol Zoo Gardens for the majority of every day so he could both smell and communicate with them whilst he was with his human carers.

It became clear that one of the our other female gorillas, Kera was showing positive signs of wanting to care for Hasani and at eight months old, and after many successful meetings between the pair, Hasani was handed over to his surrogate.

“We couldn't have wished for a better result,” said Sarah Gedman, Team Leader of Mammals.

“We had attempted on multiple occasions to give birth-mum Kala another chance to look after him but despite her seeming very keen to begin with, we started noticing the worrying signs of her not being able to cope.

“After several weeks, we just had to accept that it wasn’t working but fortunately we had another female showing very positive signs that she wanted to do the job.

“Kera and Hasani are wonderful to watch. He will giggle with delight when she plays rough and tumble with him. He is very relaxed amongst the troop and is finding his place in the hierarchy.”

‘A typical, energetic boy’ – Bristol Zoo Gardens’ surrogate-raised gorilla turns one

Despite being a little shy of the adults in the troop, keepers say Hasani enjoys instigating play with smaller members, youngsters Ayana and Juni. He’s very respectful of silverback Jock – a natural and reassuring behaviour to see from a younger male.

The infant enjoys a varied vegetable diet alongside his milk, including his favourite foods of cucumber, steamed carrot, tomatoes and romaine lettuce.

The wild population of western lowland gorillas is estimated at around 360,000. Many gorillas are killed for the 'bushmeat' trade where animals are shot by hunters and the meat sold to traders in towns and cities.

Because there are so few in the wild, Bristol Zoo Gardens, among other worldwide zoos, are actively involved in ensuring there is a strong population in human care through captive breeding programmes, which form the EAZA Ex situ Programme (EEP).

As well as this, around 4,800 miles away, conservationists from Bristol Zoological Society and universities in the UK are currently working to protect declining numbers of the species in the wild at Parque Nacional de Monte Alé, in Equatorial Guinea.

Their work from a research base camp within the National Park includes forming partnerships with government agencies in Equatorial Guinea to facilitate research collaboration and further ape conservation in the region.

It also involves establishing standardised great ape (and other large mammal) monitoring programmes, including training in monitoring methods for personnel; reinforcing capacity and structures for effective law enforcement support for the recruitment, training and deployment of eco-guards in the national park; and the ongoing support of Ape Action Africa, a Cameroon-based wildlife aid fund. 

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