By Alex Kirby
BBC News Online environment correspondent
A huge tropical bat which could soon be extinct in the wild appears to be doing well in captivity in a British zoo.
The bat is one of the world's largest and most endangered
A colony of Livingstone's fruit bats, whose wingspan can reach 5ft (1.5m), has been kept at Jersey zoo in the Channel Islands for the last 12 years.
A number of the bats have now started to fly through a purpose-built tunnel in their enclosure in search of food.
The zoo, HQ of the Durrell Wildlife Conservation Trust, is one of only two global sites where the bats are kept.
Livingstone's fruit bat (Pteropus livingstonii), also known as the Comoro black flying fox from its home in the Comores Islands near Madagascar, is thought to be at risk of imminent extinction because of the loss of its forest habitat.
The trust is working with a local group, Action Comores, to save the species. It now has 30 bats on Jersey; another colony is at Bristol Zoo Gardens.
The trust says it is necessary to keep the animals in captivity in order to encourage breeding, learn more about their needs and behaviour, and save them from extinction.
The colony helps to sustain its environment
Until now they have never been known to fly successfully for any distance in captivity. But some have begun flying the full length of a 130ft (40m) tunnel, planted with vegetation to encourage them to fly to reach their feed.
They are also proving their ability to sustain their own environment. Dozens of wild tomato, fig, melon and cape gooseberry plants are now growing in the tunnel's earth floor, having germinated from seeds which had passed through the bats.
Two young bats have been born in the tunnel this year, suggesting the animals are happy with it.
Dominic Wormell, deputy head of mammals at the zoo, said: "Of the some 950 species of bat that live worldwide, Livingstone's fruit bat is one of the largest and faces the greatest risk of extinction.
"In the Comores, precious little forest remains - the islands are also home to a poor and rapidly expanding human population. If areas that the bats depend on for their survival are not protected, this amazing species will be extinct within 10 years."
Mark Stanley Price, executive director of the trust, said: "Durrell Wildlife's success with the bats in the Comores is building on the back of its Islands & Highlands programme.
"This has identified concentrations of unique and rare species, which have evolved together and are found only within very small areas and nowhere else on Earth.
The flying foxes attract visitors
"Islands and highlands make up only 5% of the globe's surface but account for 45% of its endemic animal and plant species; and of the 724 known animal extinctions in the last 400 years, half were on islands."
There are thought to be about 1,000 bats on the two Comores islands where they survive in the wild.
The bats are mostly covered in very dark brown-black fur, have rounded ears and large orange-brown eyes.
Adults have a body length of about 1ft (30cm). On average they weigh 1.1 to1.8lbs (500-800g), although bats born in captivity tend to be heavier as they generally fly less and eat more.
Images courtesy of Richard Wainwright.