Sleeping Beauty

Thursday 22nd September 2016

Darren Tansley, our Water for Wildlife Officer, co-author of “The Mammals of Essex” book and also a licensed Dormouse handler, provides an update on Dormouse surveying in Essex and Suffolk:

The Essex and Suffolk Dormouse Group was formed at the turn of this century, to search large areas of the two counties for this charismatic but elusive animal; we now know that Dormice mainly reside east of the A12 in Essex and no further north than mid Suffolk. There are other important clusters, with one of the most significant in Hadleigh Great Woods (monitored by the Southend Dormouse Group).

Despite 15 years of surveying, Dormice are still considered rare, with colonies fragmented in the two counties. More worrying is that the survey techniques used by some developers to find Dormice may not be picking up these vulnerable animals before sites are cleared.

So, this year more than 1,000 survey tubes have been installed across the two counties, monitored by staff of Essex and Suffolk Wildlife Trusts and volunteers from the Essex and Suffolk Dormouse Group. The tubes will be checked at the end of each month by licensed handlers and experienced volunteers in what is the largest study of its kind since the original survey method was developed. The surveyors are counting the number of distinctive Dormouse nests found in the tubes, along with the sex and weight of any Dormice found in them at the time.

While the main reason for the survey is to see how effective it is at identifying Dormice, a side project is also under way simultaneously. Previous DNA studies of Suffolk Dormice have identified that they are an entirely separate population from the rest of the UK, suggesting that they must have been isolated shortly after colonising Britain. So, on a number of sites along the Essex/Suffolk border, special licences have been granted to take DNA samples from any live captures, to ascertain where the split begins. Are these populations separated by the River Stour, or was there some other barrier to their movement in the past?

What is certain is that this amazing woodland, native animal continues to pop up in new locations and that it is vital that every effort is made to look for them before sites are cleared for housing or industrial use.