Dozens of young male gorillas in UK and European zoos face being castrated as part of a plan to make them more manageable, reports say.

Scientists apparently want them to develop more like "butch" females instead of turning into "silverback" mature males which are very strong and can be aggressive and difficult to look after.

As the young males get older they start to challenge their fathers and have to be kept separately or in bachelor groups which can create more problems with how they are managed.

Also there tends to be a surplus of males - as gorillas produce equal numbers of males and females but they go on to live in harems of one male to two or three females.

Castration involves the apes having their testicles surgically removed.


Mbula and Mwana, young males living in Chessington Zoo, have been castrated.

The castration programme is overseen by the European Association of Zoos and Aquaria (Eaza).

Eaza director of communications David Williams-Mitchell told The Sunday Times that castration was an "ethical alternative".

He added: "Carried out at a young age, [it] prevents development of the full range of adult male characteristics and behaviours... research points to castrated animals continuing to live in their original family groups with no problems."

Mbula and Mwana are in a research group of 11 gorillas who have had the surgery over the past decade, according to the newspaper.

A study involving 75 male and female gorillas of all ages - including 10 males who have not had the operation - found the castrated ones were more often tolerant of being near other gorillas than ones who had not had it.

Now some young gorillas are on so-called "castration row", awaiting a decision by scientists as to whether they will be allowed to develop into fully equipped adult males, the paper added.

Gorilla's makeshift hay umbrella

There are 40 male and 60 female gorillas in British zoos.

At least one owner, the charity The Aspinall Foundation, which runs Howletts Wild Animal Park and Port Lympne Reserve, both in Kent, is against moves to castrate gorillas.

Anti-zoo campaigners have also hit out at the idea.

Dr Chris Draper, head of animal welfare and captivity at the Born Free Foundation, told Sky News: "It's a classic example of making the animal fit the environment rather than the other way around."

Born Free is against the "exploitation of wild animals in captivity" and Dr Draper described castration as "a pretty drastic step".

Speaking about the surplus of males outside the harems, he said: "In the wild, gorillas move about in groups. The males would have a chance of forming a group. It's not possible in a captive situation."