England's only wild beavers give birth - the first known new arrivals for the species in 400 years

The only colony of wild beavers left in England has had a litter of babies - the first to be bred in the country in almost 400 years, conservationists have revealed.

The youngsters, known as kits, have been spotted taking their first swim and hitching onto their mothers' backs through the waters of the River Otter in Devon.

Retired scientist and wildlife buff Tom Buckley managed to snap pictures of the tiny creatures venturing into the open, and said he was "totally overwhelmed" by the sight.

The colony of beavers has been living wild on the river for between three and 10 years, making a surprise return after the species was hunted to extinction in the UK hundreds of years ago.

Their origin is not known, but is thought to be the result of an escape or unauthorised deliberate release.

Government ministers drew up plans to capture the creatures and keep them in captivity after evidence emerged last year that they may be breeding.

But following public outcry and a vocal campaign, the beavers were simply tested for disease before being released back into the wild.

Their impact on the river and surrounding countryside is being monitored by Devon Wildife Trust, who has asked dog walkers and visitors to keep dogs on leads and stick to footpaths to avoid disturbing the new arrivals.

Trust spokesman Mark Elliot said they were "thrilled" that the beavers had given birth.

Beavers have three kits per litter, on average - meaning if both mothers on the river have given birth, the population may now have expanded to 15.

Wildlife groups claim the return of the aquatic mammals, which cut down trees and dam rivers, could prove invaluable in preventing flooding, maintaining water quality and encouraging other wildlife.

But farmers and anglers have voiced concerns they might damage the landscape and fish migration routes.

They have argues that conservation efforts should be focused on the UK's existing wildlife.