The ring-tailed lemur of Madagascar is “disappearing right under our noses” as the iconic animal is hunted and trapped to extinction and its forest home destroyed by people hunting for sapphires.

Lemurs are the most threatened group of vertebrates on the planet but it was thought the resourceful ring-tailed species – which featured in the hit cartoon film series Madagascar and the BBC's recent Planet Earth II documentary – would be the last to die out.

However, despite their ability to survive in some of the harshest environments on the Indian Ocean island, they have been mostly reduced to small groups, researchers warned in a paper called Going, Going Gone: Is the Iconic Ring-railed Lemur Headed for Imminent Extirpation? in the journal Primate Conservation.

Populations of more than 200 were found in just three places, with 12 other groups of 30 animals or less. At another 15 sites, they had either died out or were in danger of doing so. In total there are now believed to be less than 2,500 individuals.

One of the researchers, Professor Michelle Sauther, who has studied the animal for 30 years, said: "This is very troubling. They are disappearing right under our noses.

“It's likely that the ring-tailed lemur population will eventually collapse.

“We are getting an early warning that if we don't do something very quickly, the species is going to become extinct.

“And this is the one primate species in Madagascar we never thought this would happen to.”

The plight of the ring-tails suggests the other lemur species will also be struggling.

“Ring-tailed lemurs are like the canary in a coal mine,” said Professor Sauther, of the University of Colorado Boulder in the US.

“If they are going down the drain, what will happen to the other lemur species on the island that have more specific habitat and diet requirements?"

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One threat to lemurs is the creation of open-cast sapphire mines that have drawn in thousands of people in search of their fortunes, on an island where 90 per cent of people live on less than $2 (about £1.60) a day.

This has led to the destruction of significant areas of the lemurs’ forest habitat and an influx of people who need to be fed, increasing hunting for bushmeat. Lemurs are also captured and sold for an illegal pet trade, boosted by the popularity of the DreamWorks’ films.

Professor Sauther said: “I think it's important to keep in mind that what is driving habitat loss and ring-tailed lemur declines is human poverty.”

Fellow researcher Professor Lisa Gould, of the University of Victoria, said many areas that once contained important populations of ring-tailed lemurs now had none.

“It was important to try and document as many populations of ring-tailed lemurs in as many regions as possible,” she said.