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Invasive non-native species (UK) – Edible dormouse

edible dormouse non-native invasive species

This week’s article, part of our invasive non-native species series, focuses on the edible dormouse…

The edible dormouse (Glis glis) are thought to be native to continental Europe and were introduced into Tring Park in 1902.  Edible dormice have established populations in the Chilterns and the species may also be established in the New Forest, Hampshire, Essex and the Oxford area.  Reports in 2010 suggest that the UK has seen an explosion in the population in recent years – numbers could be as high as 30,000.

The common name of the edible dormouse comes from the Roman practice of fattening this type of dormouse to be eaten as a delicacy.

edible dormouse

Identification & Ecology
Identification features of the edible dormouse include pale grey fur, with a white underside and a long, bushy grey tail. The body of an edible dormouse is no longer than 20cm in length, in addition to a tail of up to 19cm. The tail is usually held flat, with a thinner tail than the grey squirrel. The legs and soles of the feet have naked, rough patches which aid the edible dormouse when climbing. Male and female edible dormice are similar in size and appearance, whilst juveniles are a slightly duller grey than adults.

Edible dormice inhabit woodland, parkland and gardens. They tend to avoid coniferous woodland and pine plantations.

Edible dormice are rarely seen, because of their nocturnal behaviour and long hibernation (September to May). They come down to the ground to hibernate in response to low temperatures and reduced food availability, finding sites under tree roots or in the burrows of other animals. They can enter houses or caves for food and shelter.

Impact
Edible dormice can cause problems for householders with their readiness to enter houses and outbuildings. This can be either as noise disturbance, or through property damage, chewing through timbers and wires in roof spaces, defecating in roof voids and occasionally drowning in water tanks.  They are often found in groups; up to 30 have been removed from the attic of a single house.

There is also thought to be an economic impact when damage is caused to trees by bark stripping and ring barking, they are also known to eat fruit crops. In some areas the edible dormouse may compete with hole-nesting birds for nest boxes, and potentially threaten some species by eating their eggs and young.

edible dormouse

Legislation
Legislation which attempts to control the distribution of edible dormice includes Schedule 9 of the Wildlife and Countryside Act, 1981 (as amended), which makes it illegal to distribute or allow the release of edible dormice into the wild. The legal status of the edible dormouse in the UK can be confusing as it is also illegal to trap the species without a licence.

Control Measures
Within the UK, management techniques for the edible dormouse include capture of the individuals. The methods used can be either live capture traps, or spring traps (both subject to a Natural England licence).

References:

About the Author: Elizabeth Kimber works for an ecological consultancy based in Dorset (Lindsay Carrington Ecological Services Ltd). As part of the role she manages the ecological works for a multi-phase development. She conducts protected species surveys and holds a class 1 bat licence, smooth snake and sand lizard licence. She can be contacted via email: liz (at) ecological-services.co.uk.

2 Comments

  • This article seriously underestimates the numbers of Glis glis found in the Chilterns – where there could easily be 300,000 causing serious problems, with woodland birds and hazel dormice suffering.