The illusive incredible edible dormouse

This post comes from Sarah, our Conservation Management Officer. It also featured in the blog of The Wild Outside, a site dedicated to citizen science.

The illusive incredible dormouse copyright Sarah Brooks (WWT)
The illusive incredible dormouse copyright Sarah Brooks (WWT)

In my previous job roles I was lucky enough to work closely with dormice. Not just the common hazel dormouse, but the less-common edible dormouse as well. Unfortunately when the recession hit in 2008, funding got cut for most research projects. However, those of us involved had too much passion for nature conservation and ecological knowledge to let that be the end of the projects! So a dedicated group of volunteers continue to do this valuable research, despite having little or no funding to do so.

Our native hazel dormice in torpor copyright Sarah Brooks (WWT)
Our native hazel dormice in torpor copyright Sarah Brooks (WWT)

Alongside my job at the Wildlife Trust, I am also an active member of Warwickshire Dormouse Group. The group is one of the most enthusiastic I have ever met! This is because there are so many active members carrying out surveys, installing nest boxes and tubes and carrying out habitat improvement works for dormice in the hope they will see some. Unfortunately, Warwickshire is at the edge of the nature range of the hazel dormouse, and as a result, there are not many populations in the county. So I thought I would take the group to one of the research sites I am involved with in the Chilterns where there are plenty of dormice to see! Plenty of edible dormice that is!

Edible dormice (aptly named as the Romans used to eat them and some eastern European countries still do!) are a non-native species in Britain. They were brought to Tring Park by Lord Walter Rothschild in 1902 as part of his exotic zoological collection. They escaped from here and have since spread throughout the Beech woodlands of the Chilterns. Whilst they look cute, they can cause problems in this country as they are non-native and have few natural predators. They bark strip trees in the same way as grey squirrels, they predate on our native bats and woodland birds, plus they can get into peoples houses – leaving droppings, chewing through wires and eating food.

Pat Morris is a retired lecturer from Royal Holloway university who started monitoring the population in the Chilterns in 1996. The study was taken over by Forest Research in 2007 and when funds were cut in 2009, volunteers ran the project using money from their own pockets to continue this invaluable research. We monitor population and breeding trends of this intriguing little creature. They differ considerably from other small mammals in this country. Firstly, they hibernate for 7 months of the year during the winter. Secondly, their breeding appears to be dependent solely on Beech mast. So when the Beech trees produce a lot of flower and fruit, animals can have a litter of up to 10 in a year. Years when the Beech mast is very low, not a single animal will breed. Animals are also very long-lived. The use of PIT tags (the same as those used on pet cats and dogs) means that we can individually identify animals out in the field. Not only do we know that animals are social and nest communally, we know they occupy the same home range for many years and that some animals have reached an age of up to 14 years!

Edible dormouse in an underground cavity during winter hibernation copyright Sarah Brooks (WWT)
Edible dormouse in an underground cavity during winter hibernation copyright Sarah Brooks (WWT)

Some of the long-lived animals that we see regularly seem to completely disappear in the ‘non-breeding’ years. Where do they go? This is something we are trying to discover through the use of radio tracking. Last autumn we managed to get a small amount of funding to carry out this bit of research – if this year proves to be a non-breeding year, then we will be able to track animals to see where they disappear to in these times. One theory is that they remain in hibernation all through the summer, appearing for a short time only to discover there is no food for them so go back to sleep. Another theory is that they migrate somewhere else where there is food – perhaps people’s houses. Hopefully this research will spread some light on this intriguing question.

Edible dormouse wearing a radio collar for tracking copyright Sarah Brooks (WWT)
Edible dormouse wearing a radio collar for tracking copyright Sarah Brooks (WWT)

Unlike edible dormice, hazel dormice are a native species and are legally protected in this country. As they require a rich and diverse habitat to survive, they are a great indicator species of other wildlife. Conservation work for dormice will also benefit a multitude of other species. I think the Warwickshire Dormouse Group enjoyed their day out and hopefully it gave them motivation to carry on their good work in the hope that one day, we’ll find a new dormouse colony in Warwickshire.

I think this shows how volunteer effort can really make a difference to our ecological knowledge and nature conservation. So if you feel inspired to help, join your local record group or Wildlife Trust as they need people like you to help with surveys and conservation management.



1 thought on “The illusive incredible edible dormouse”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s