Dormice under threat from poor woodland management

Better management of woodlands is needed to help stop the decline of Britain’s dormice, new research suggests.

Dormouse numbers are falling in Britain – down by 72% in just over 20 years – and the scientists say this could reflect changes in climate and the composition and structure of woodland habitats.

The findings, from two new studies led by the University of Exeter, show dormice favour woodland with varied heights and areas of regrowth, including species such as hazel and yew that provide the flowers, fruits and nuts they enjoy.

Dormouse numbers are higher in woodlands with more varied tree heights and scrubby areas, and they prefer to use areas of woodland edge, and dense trees and shrubs, when they move around at night.

“Habitats that we found to be good for dormice have been in decline,” said lead author Dr Cecily Goodwin.

“Dormouse conservation would benefit from more broadleaf woodland in the landscape and more diverse woodland structure – ranging from new growth and scrub to mid-height woodland to old trees.”

Professor Robbie McDonald, who directed the research, said: “There has been a decline of woodland management that creates diverse forests, and an increase in large stands of mature, single-age trees, which are not such good habitats for dormice or various other declining woodland species, such as some birds and butterflies.”

Wildlife charity, People’s Trust for Endangered Species, has been collecting population data on hazel dormice for over 20 years.

Using its data from 300 sites across England and Wales, the researchers investigated hazel dormouse numbers, breeding and population trends in relation to climate, landscape, habitat and woodland management.

Nida Al-Fulaij, from the charity, said: “We have been working hard to understand the ecology of hazel dormice and the conservation issues they face for over 20 years.

“With data collected by hundreds of dedicated volunteers, this research will enable us to work closely with woodland owners to ensure a brighter future for one of Britain’s best loved animals.”

A further study found that hibernating dormice benefit from consistently cold winters and climatic changes in Britain are likely to have contributed to dormouse declines.

Researchers said variable winters were most likely to cause the sleepy rodents to waste energy by waking up only to return to hibernation.

– The papers, Habitat preferences of hazel dormice Muscardinus avellanarius and the effects of tree-felling on their movement, is published in the journal Forest Ecology and Management and, Climate, landscape, habitat, and woodland management associations with hazel dormouse Muscardinus avellanarius population status, is published in Mammal Review.