The 60-year-old personality tweeted: “What could be nobler than saving a beautiful bat from extinction?”

His support helped the crowd funding campaign by University of Bristol PhD student, Sarah Richdon, reach its target of £7,500 ($10,000).

She will use the money to produce the genetic family tree of all the bats in captivity at Bristol Zoo and Jersey Zoo and by comparing their genetic finger-prints.

Sarah, who works part-time as a volunteer co-ordinator at Bristol Zoo Gardens, said: “I am overwhelmed that Stephen would so enthusiastically and willingly support our cause by pledging and tweeting about it.

“I can’t thank him enough. It means the world to us and could help secure the future of this campaign – and the future of Livingstone’s fruit bats.

“Only with conservation in the field and in captivity can this species survive and, thanks to the support of Stephen Fry and all the wonderful people who generously donated, I hope to be able provide essential research to this effect.

“It is important that the information I find is in the public domain so that everyone can benefit.”

Financier Simon Cavill, brother of Superman actor Henry Cavill, also donated to the appeal.

The campaign finished with 104% of funding and Sarah can now go ahead with her research.

At present there are fewer than 1,300 Livingstone’s fruit bats left in the wild. In captivity there are just 70 precious individuals, of which 11 are at Bristol Zoo Gardens.

Sarah, who is currently doing her PhD at the University of Bristol, said it was possible to bring back species from low numbers.

Livingstone’s fruit bats are found in the wild on the Comoro islands in the Indian Ocean north-west of Madagascar. In recent years, more than 45 per cent of the Comoros islands have been transformed into agricultural land depriving the bats of their natural habitat.

It has also affected the eco-system as bats are crucial for re-forestation because they disperse seeds across the island.

Sarah became fascinated with fruit bats when she was a volunteer at Bristol Zoo for 18 months.

She said: “I knew I wanted to do research. I started to look into the fruit bats and discovered there was very little known about them.

“They are highly social animals that live in large groups and each one has its own personality.”

It will take Sarah two years to complete her genetic research and five to finish her PhD but she intends to publish her findings as she goes along.

“It is important that the information I find is in the public domain so that everyone can benefit,” she said.

Follow Sarah’s findings at: www.experiment.com/batonthebrink