Latin name: Muscardinus avellanarius
Hazel dormice were formerly widespread in woodland across Britain but there has been a considerable decline in both range and numbers in the last 100 years. This has primarily been as a result of changes in woodland management, primarily the loss of coppiced Hazel woodland, the loss and inappropriate management of hedgerows and increased isolation of suitable woodland habitat.
Despite some unsubstantiated reports in some areas of Yorkshire in recent decades, there is good evidence that dormice had become extinct in the county of Yorkshire during the preceding hundred years. As part of the national Species Action Plan (SAP) for Dormice that was published in 1995 one of the key aims was to ‘maintain, enhance and re-establish Dormouse populations within their historic range’. Following several reintroduction programs in Yorkshire at a site in the North York Moors National Park in 1999 and near to West Tanfield in 2004, Freeholders’ Wood near Carperby in Wensleydale was assessed to determine the suitability as a further reintroduction site. This led to a collaborative project involving the People’s Trust for Endangered Species, Yorkshire Dales National Park Authority, Natural England and the Common Dormouse Captive Breeders Group that resulted in 35 captive bred animals being released into Freeholders Wood.
Monitoring work that has been undertaken as part of the National Dormouse Monitoring Program involves licensed fieldworkers checking nest boxes once each month from May to October and recording the number of Dormice nests, adults and or young. This work has shown that since the original reintroduction, the population has increased and continues to spread through the woodland. The Yorkshire Dales National Park Authority will continue to manage Freeholders’ Wood as coppiced woodland and are working with neighbouring landowners to try and create links to adjacent areas of woodland so that the dormice will hopefully spread into surrounding areas of woodland.