A colour-changing frog has turned blue in the UK for the "first time in 700 years".

A frog

A frog

Male moor frogs are common in Europe and turn blue in spring as they prepare to mate as it tries to impress the females and it is believed to have done so in Britain for the first time in centuries after an experiment.

Teenagers Harvey Tweats and Tom Whitehurst created a breeding enclosure in a small bath and played the frog sounds of male mating. This caused the animal to think it was surrounded by rivals and turn blue as a result.

The pair, who own the Celtic Reptile and Amphibian breeding company, told the Daily Telegraph newspaper: "It’s the first time one’s gone fully blue in Britain for 700 years."