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Species Dormouse - Muscardinus avellanarius, mammal
Habitat SPECIES RICH HEDGES, UPLAND OAKWOOD, WOOD PASTURE AND PARKLAND
Background and status This attractive, agile mammal grows to 6-9 cm, with a slightly bushy tail which is almost as long as its body. It has orangey-brown fur, small ears and black eyes. It is mainly nocturnal and arboreal. In summer it lies up by day in a round nest (10-15 cm in diameter) of leaves and bark which is usually placed at a height of 1-4m in trees.

The dormouse eats hazelnuts, acorns, beechmast, bark, shoots, flowers, berries and other vegetation (and some insects). Particularly important components of its habitat (for food and shelter) are: hazel, oak, honeysuckle and bramble. Young (usually 3-4) are born in June/July (sometimes a second litter in late summer) which leave the nest after a month, becoming fully independent 10 days after. In October dormice roll into a ball in their winter nests (built in a hole in the ground, in tree roots, coppice stools and dense undergrowth) and hibernate usually through to April/May.

Dormice breed in the summer following their birth and can live for 3-4 years. The dormouse does not cross open country, so distances as little as 100m (eg, wide rides) are barriers unless arboreal routes (such as overarching and connecting tree branches) exist. The dormouse also uses bird nest boxes and special `dormouse boxes’ are useful in monitoring studies.

Found in Britain mainly in the West and South (does not occur in Scotland or Northern Ireland and in Wales and has been lost from half its former range (mainly from Wales and northern England) in the past 100 years. Now only widespread from Devon to Kent, where population densities, even in good habitats, are less than 10 adults per hectare.

Main Threats

Continued loss and fragmentation of its habitats, leaving isolated, non-viable populations.

Changes in and cessation of woodland management practices, such as coppicing, which reduce suitable habitat.

Stock incursion into woodlands (grazing removes undergrowth habitat).

Loss of old hedgerows, loss of hedgerow networks, inappropriate management (eg, frequent cutting removes food sources and nest sites).
Conservation and targets

Maintain and enhance existing populations and range of dormouse.

Re-establish self-sustaining populations in at least five counties in their former range.

Ensure planning policy adequately safeguards existing dormouse populations (development can destroy and fragment habitats).

Ensure appropriate conservation and management of existing dormouse habitats.

Advise land managers on sensitive management, in tandem with promotion of appropriate grant schemes (eg, Woodland Grant Scheme, Countryside Stewardship).