Zoo sets up sperm bank to save rare species of big cat from extinction

Hopes have been raised for the future of three endangered species of big cat, after London Zoo announced the creation of a sperm bank and launched a worldwide appeal for donations.

The project has been set up in response to the decline in numbers of the Amur (or Siberian) tiger, Amur leopard and Sumatran tiger. The intention is to freeze the sperm and have it ready for zoos and others to use for artificial insemination as the species near extinction.

There are an estimated 400 Amur tigers in the wild, and just 30 Amur leopards. WWF, the global environment network, has put the number of Sumatran Tigers left in the wild at between 400 and 500.

It is believed that, in captivity, there are as many as 400 to 500 Amur tigers, about 200 Amur leopards and 400 to 500 Sumatran tigers. The sperm bank is the first of its kind to be set up by the zoo.

Sarah Christie, the London Zoological Society's big cat expert, said: "The situation for big cats is critical and we need to act now to safeguard them for the future. The zoo is working out in the field to protect these animals in their natural habitat, but given the small number of Amur leopards, Amur tigers and Sumatran tigers left in the world, we need to do all we can to ensure the continued survival of these magnificent animals."

For sperm collection to take place the big cat must be anaesthetised, so the society is asking zoos and nature reserves to collect the sperm only when the cats are in for an operation.

Some samples have already been taken at London Zoo, which employs a technician to collect sperm. "It's a job not many people would fancy," a Zoological Society of London spokeswoman conceded yesterday. The zoo has a male and female Amur leopard, and a male and female Sumatran tiger, but no Amur tigers.

The Amur (or Siberian) tiger is one of the largest and heaviest subspecies of tiger, with long, fine fur and a layer of fat to protect it against the cold. An adult male can be up to 10ft long and weight up to 800lb (360kg). The Amur (or Far Eastern) leopard is found near the Russian border with China. It weighs up to 110lb. The Sumatran tiger, one of the smallest subspecies of tiger, is found in the island of Sumatra, Indonesia and weighs an average 265lb.

"We're doing everything we can - from captive breeding to the sperm bank to working out in the wild with them," the society's spokeswoman said. Sperm banks have been used before to save species. A few years ago zoologists began collecting semen from 30 of the surviving 44 male South China tigers.