Toads particularly are not very palatable

Joe Harper, Environment Agency

Many thousands of frogs have been killed by a virus that has spread from the south east of England and into Scotland.

The virus attacks the frogs' legs.

But scientists are satisfied otters are to blame, even though mass killings are rare.

They say there is a simple explanation for their victims' legs being mutilated.

Toxic lunch

Joe Harper, a conservation officer with the Environment Agency, said: "They are probably the tastiest bits.

"Toads particularly are not very palatable.

Otters have been blamed for the frog deaths

"They have fairly toxic skin so the animals will remove the legs and skin them, and take the meat within."

Farmer Oliver Edwards said: "I was very concerned because it was wiping out our frogs.

"We like to see small frogs and all the other things that go with conservation areas.

"To wipe out the frog population in the food chain is not very good.

"I'm glad that the otters are here and long may it last, but I'm not so happy that they are eating my frogs."

Checks have confirmed that amphibians are still surviving around Mr Edwards' pond - at least for the time being.