Edible dormouse that Romans enjoyed as delicacy is named as Britain's No 1 pest

In Roman times, they were fattened, stuffed and served as a delicacy. 

But 2,000 years later, the edible dormouse has moved off the menu to become one of the greatest threats to our native woodland, a report warned yesterday. 

The grey-brown mouse was accidentally introduced into the UK ecosystem 100 years ago after escaping from a zoologist's private collection.

There are now around 30,000 of the grey-brown rodent in the wild, causing widespread damage to woodland by stripping bark from trees, and destroying fruit crops such as apples and pears.

Cute but threatening: The 30,000 dormice in Britain, are damaging woodland by stripping bark from trees and destroying fruit including apples and pears

It has now been listed in a new report on 14 invasive foreign species, including the muntjac deer and the grey squirrel.

The animal, which is also known as the fat dormouse, has been known to chew through wiring in houses. It is related to the endangered hazel dormouse, a native British species.

The edible dormouse escaped from Lionel Walter Rothschild's private collection near Tring, Hertfordshire, in 1902. Its main population is in the Chilterns but it has spread as far as Essex.

It is common in Europe and was famously eaten as a delicacy by the ancient Romans. 

Celebrity chef Heston Blumenthal cooked one as part of his Christmas dinner show for Channel 4 last year.

The authors of the report, commissioned by The People's Trust for Endangered Species, say the edible dormouse has been overlooked as a threat because of its cuddly appearance.

Pests: Muntjac deer and grey squirrels join a list of 14 invasive foreign species 

Professor David MacDonald, a zoologist at Oxford University, said: 'There is quite a lot of inconsistency in people's reactions to invasive species. The edible dormouse is quite widely thought of as being quite cuddly and so it doesn't seem to be worrying people, but we just don't know how much of a problem it will turn into.

'It has been increasing in numbers quite a lot recently although is still fairly confined in its range. We have seen with other invasive species, they can become a blight.'

His report, State of Britain's Mammals, lists American mink and grew squirrels as the most damaging non-native species to have become established in the UK.

Mink is thought to have escaped from fur farms around 1929 and has decimated the native water vole population. 

Grey squirrels, introduced within the past two centuries, have led to a dramatic fall in the red squirrels known from the stories of Beatrix Potter.

Also on the list are red-necked wallabies, which have escaped into the wild from zoos and private collections and now exist in the Peak District, Bedfordshire and an island in Loch Lomand.

The report warns that other species have the potential to become future threats: including prairie dogs, short-clawed otters, raccoons, skunks and chipmunks.

Trevor Reynolds, invasive species advisor for the Environment Agency, said: 'Invasive species are a kind of biological pollution.

'It is likely that with climate change, the UK will see far more invasive species emerging. Stress caused to habitats by climate change will allow invasive species to take hold while increased storms could help spread invasive species around.'