Britain’s native hazel dormouse (Muscardinus avellanarius) has declined by a third since the start of the 21st century, reveals a new report published today [Friday 9 September] at the National Dormouse Conference by wildlife charity People’s Trust for Endangered Species (PTES).

The State of Britain’s Dormice report also finds that dormice are extinct in 17 English counties since the late 1800s.

PTES manages the National Dormouse Monitoring Programme (NDMP) - the longest-running small, terrestrial mammal monitoring project in the world. Since 1988, volunteers across the UK have collected 100,000 records, providing a significant data set which indicates how the species is faring.

Once a familiar sight throughout much of England and Wales, over the past 100 years dormice have suffered from the loss of woodlands and hedgerows, as well as changes to farming and woodland management practices. As a result, the species is now rare and vulnerable to extinction.

Dormice populations are also vulnerable to climatic changes, in particular wetter springs and summers, when foraging for food becomes harder, and when warmer winter temperatures interrupt successful hibernation.

PTES is a major contributor to other studies, and NDMP data has been used in the State of Nature, a report published by a coalition of leading conservation and research organisations. The first report in 2013 showed that 60% (sixty percent) of UK species had declined over recent decades. The second State of Nature report will be launched by Sir David Attenborough and UK conservation charities on Wednesday 14 September 2016.

Ian White, Dormouse Officer at PTES said: “Dormice have been around for 40 million years, but their future in Britain is now precarious and there’s a pressing need for action to ensure their long-term survival. Protecting dormice is a priority for PTES: along with the support of hundreds of volunteers, we are trying to save them before it’s too late.”

PTES has a three-pronged approach to reversing the decline in dormice, which includes: recording dormice, providing training and guidance for woodland managers and landowners, and a reintroduction programme.

The reintroductions play an important role in the long-term conservation of this protected species and are part of Natural England’s Species Recovery Programme. Between 1993 and 2016, PTES has managed 26 dormouse reintroductions at 22 sites in 12 counties with 864 animals released; 21 of the reintroductions have shown indications of success, such as breeding or dispersal to new areas beyond the site.

The National Dormouse Conference, managed by PTES, takes place at the University of Reading on 9 and 10 September 2016.