The chances are that you have only seen this fugitive in cartoons. He is instantly recognisable by his protruding front teeth, sleek coat and tennis-racket-shaped tail – and the trail of pencil-point-perfect tree stumps that he leaves in his wake.

Five hundred years after they were hunted out of extinction in Britain, the beaver is once again living wild in England. But freedom may be fleeting for the oversized rodent, which has been leaving a trail of neatly gnawed trees along a Cornish riverbank.

The six-stone (38kg) runaway, described by his owner as “a very big boy”, was one of three beavers that escaped from a wildlife sanctuary at Lifton, Devon, in October, when an electric fence broke. Two, both females, were swiftly recaptured, but the male appeared to have vanished completely - until two weeks ago.

That was when people 20 miles away in Gunnislake, Cornwall, began to notice a rash of felled trees along the banks of the River Tamar. Exactly how many trees the fugitive has felled since his escape remains unclear, because many of the riverside sites that he has visited are off the beaten track. But the signs are unmistakable. Shavings created by chisel-like teeth lie in neat circles around the stumps, leaving little doubt as to the identity of the culprit, even to those who had only ever seen a beaver on television.

The beaver’s owner, Derek Gow, who is building traps in the hope of recapturing his prize specimen, said: “I would think it’s more like two or three [trees] a week than one a day. If anyone loses an apple tree I will personally replace it, but that is unlikely.

“I’ve been keeping [beavers] since 1994, but this the first time one has escaped. He’s looking for a lady beaver so we will bait a trap with scent from one of the females. He won’t be able to resist.”

For the time being, however, a shortage of beaver traps is hindering progress. “Beavers haven’t lived here since the 13th century and so traps are in short supply. They don’t exactly sell them at B&Q,” Mr Gow said.

The animal sleeps in a submerged riverside burrow during the day, only emerging to nibble the vegetation at dusk. Although there have been no reported sightings, Mr Gow is in no doubt that the fugitive has been traced.

The beaver escaped from the 120-acre Upcott Grange Farm, where Mr Gow keeps 24 beavers under licence. Some are in quarantine for six months, before being released in Scotland as part of a reintroduction programme approved by the Scottish Executive.

He believes that the beaver is trying to build a dam in the hope of attracting a female. If so the animal is out of luck twice over. Mr Gow said: “This is the only beaver living wild in England, so there aren’t any females out there to be found. Also, the Tamar is too wide and fast-flowing for a dam.”

The eight-year-old beaver was brought to Britain five years ago from Bavaria. Beavers were hunted extensively here during the 12th century and disappeared from the rest of Britain 400 years later. They were hunted for their fur and anal glands, which were believed to have medicinal properties. Mr Gow said: “In the Middle Ages, it was an incredibly valuable animal to kill. If you could kill a beaver, it would be three years’ wages.”

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