Hazel dormouse surveys are currently in full swing. These started in April, with August and September being key months for identifying potential presence.
Special licences from Natural England are required to survey this species, which are typically associated with species rich hedgerows, scrub and coppiced woodland. They can also be found in dense scrub, conifer and plantation woodland on occasion. For the surveys, dormouse nest tubes are placed in hedgerows and hung on trees, with checks made monthly to search for signs of nest activity. However, occasionally, a less appealing guest can pop up!
Dan Robertson, one of our ecologists, found the much larger, more active, more aggressive edible dormouse in one nest tube recently. This species is Europe’s largest dormouse, reaching over 20cm in length. They were accidentally introduced into England from the private collection of Lionel Walter Rothschild, in 1902, and their distribution remains focused around Tring, in Hertfordshire. It is estimated that over 10,000 now live in the wild, within a 520 km2 triangle between Beaconsfield, Aylesbury and Luton.
Edible dormice regularly annoy local residents with their fondness for attic spaces and airing cupboards, and being rather put out when disturbed, they can give a sharp bite! There is some debate around whether they out-compete our native species for food and habitat, thereby posing a threat to the more mild-mannered hazel dormouse. Whilst not considered an invasive species, it is now an offence to release edible dormice into the wild, but confusingly, it is also an offence to harm them, as they are protected under European law.
The European range of the edible dormouse extends from France and Germany to Russia, excluding the UK. Resembling a bush-baby, or a small squirrel, the species has large black eyes and a long fluffy tail.