Why are Dormice Endangered?

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Why are Dormice Endangered?

As recently as 100 years ago, the dormouse was once commonly found in Britain, but today it is one of the most endangered species. Since 2000, Britain’s native dormouse population has declined by more than a third, according to a report released in 2019 by the People’s Trust for Endangered Species.

About The Hazel Dormouse

Hazel dormice are small rodents with golden fur and dark brown eyes. These tiny creatures can weigh as little as two £1 coins but can almost double their body weight just before they hibernate in winter – increasing from around 15-20 grams to 30-40 grams.

Preferring structurally diverse habitats, dormice raise their young and feed in dense woodland understory and nest in tree holes.

In the UK, hazel dormice are mostly found in southern England, southern Wales and along the English-Welsh border, however these populations are now incredibly sparse – it’s estimated that a populated area the size of two football fields will only contain four dormice.

Living off a mostly plant-based diet, dormice typically eat flowers, nectar and nuts, occasionally feeding on small insects during the summer when they can.

Why are Dormice Endangered in the UK?

As well as climate change and a reduction in traditional forest management practices, dormice are also threatened by predation from badgers, foxes and weasels, trampling by larger animals, and scarcity of food sources due to competition from other species like squirrels.

Habitat Loss and Decreased Quality

Over the years, woodland management methodologies have changed significantly – which has had a detrimental effect on the preferred habitats of hazel dormouse. Traditionally, management practices such as coppicing, glade creation and thinning would encourage new growth and create mosaic habitats suitable for dormice and other woodland species to thrive.

Now that these practices are less common, most woodland environments are uninhabitable for dormice.

Unseasonable or Extreme Weather

Unseasonable or extreme weather can affect the survival of dormice during the winter months and impacts their ability to raise healthy young – which is detrimental to overall population numbers.

Similarly, warmer winters experienced more recently because of climate change can cause animals that hibernate (such as dormice) to wake up earlier or more often than normal when food is still scarce.

Dormouse Conservation

Scientists say reintroduction is the only way to bring dormice back to the 17 English counties they have disappeared from and halt the decline in population, a number of wildlife organisations have taken on this challenge.

In June, the 1,000th captive-bred hazel dormouse was released into the wild in a UK-wide collaborative project between the People’s Trust for Endangered Species, Natural England, and the University of Cumbria.

Why are Dormice Endangered? - A dormouse found by our team

In an area that has a well-documented hazel dormice population, the Greenlight team were excited to find three dormice and a number of nests within bat boxes during a check with the Suffolk Bat Group on 30th October.

Why are Dormice Endangered? - Nests found in bat boxes by the Greenlight team

Dormouse Surveys in the East of England

With surveyors based across East Anglia, Greenlight can help with dormouse mitigation and legislation for your project. Get in touch with us today for a no-obligation chat about your needs.