Veteran broadcaster and naturalist David Attenborough has appealed for donations to save the conservation charity behind two leading British zoos, London and Whipsnade, which has been hammered financially by the coronavirus pandemic.

The short video clip, which will air on British television on Thursday, draws attention to the scientific work of the Zoological Society of London and features images of animals both in the two zoos and their native habitats.

"The Zoological Society of London has made an outstanding contribution to conservation and our understanding of wildlife for 200 years," said Attenborough, noting that the two zoos are home to over 20,000 animals, some of them endangered.

"The national institution is now itself at risk of extinction," said Attenborough, 94, who is famed worldwide for his documentaries on the natural world.

The ZSL has lost vital income after the coronavirus pandemic forced its zoos to close for the first time since World War Two, he said, urging people to make donations via the link zsl.org/justgiving.

In a separate press release, ZSL director Dominic Jermey said the zoos would be unable to recoup the money lost even though they have now been allowed to reopen, due to social distancing measures and heavily restricted visitor numbers.

"Unlike any other UK zoo, our zoos are the lifeline for ground-breaking research at the world-renowned ZSL Institute of Zoology and fund our global conservation projects – work that has never been more vital," he said.

The research includes looking into how diseases such as coronaviruses transfer from wildlife to humans, he added.