Dormice in Yorkshire

I’VE NEVER BEEN entirely convinced by the argument that ‘gamekeepers make the best conservationists’ but, if I was a dormouse about to be released into a wood as part of a reintroduction programme, I think that I’d prefer one where the populations of weasels, stoats and foxes were controlled, (‘controlled’ being a euphemism for snared and shot).

Barbara and I and other members of the Wakefield Naturalists’ Society have been invited to assist members of the Yorkshire Wildlife Trust and Yorkshire Mammal Group in their annual assessment of a dormouse reintroduction project in a large keepered wood on a private estate not far from Fountains Abbey, North Yorkshire.

There are 380 nestboxes to check, which sounds an impossible task, but they’re all numbered and arranged in lines, one every 15 or 20 yards, across sections of the wood so by dividing the lines up between small teams we make steady progress. During the entire morning only one dormouse is found, although a number of boxes contain the characteristic ball-of-wool-shaped nests of dormice but these may be old or temporary nests.

In the Box

Despite this, there’s a degree of excitement in every box you open; usually it will be empty apart from a slug or two, a few woodlice and a centipede but every now and then you’ll find a blue tit or occasionally a great tit, sitting on eggs or some of the cute yellow-gaped, fluffily ear-tufted, surprised-looking blue tit chicks. Other boxes contain wren’s nests. Wood mice use the boxes but we didn’t find one in residence today. Any box containing a paper wasps’ nest – the size and shape of an inverted onion - gets its lid replaced quickly.

One box that I opened had a nest lined with badger hairs but we couldn’t guess what had made it.

Honey-coloured Mouse

From a single dormouse in a box you can’t draw any conclusions . . . but . . . it occurred to me that the one occupied box was near the end of a woodland ride, near the southern edge of the wood so perhaps clearings or woodland edges are what they like.

The boxes are spread throughout a plantation-type woodland with plenty of broadleaved trees and coppiced hazels. I believe the wood is managed with pheasants in mind (although we didn’t see many today, perhaps because we were bustling about so much, checking out the nestboxes). I imagine that sunny clearings surrounded by dense coppice would be the ideal kind of woodland for dormice. They like honeysuckle which thrives in such places. The vines are probably a way for them to travel around and we noticed the shredded bark of honeysuckle stems incorporated into their nests.

Dormice prefer dry, well-drained boxes to the damp ones that the slugs and woodlice congregate in so in each team we had one person armed with a drill to make a hole or two in the uninhabited boxes.

Links

Yorkshire Wildlife Trust

Yorkshire Mammal Group