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Observations on Dormouse Muscardinus avellanarius Hibernation Nests
SUE WARD
5 Hall Cottages, Church Road, Frating, Essex
While checking a nearby wood in early February 2000 for any overnight deposits in regular Badger
dung pits. I found a tennis ball -sized nest amongst the leaf litter, flush with the surrounding ground.
On closer inspection I heard a high pitched 'squeezing' sound and, by gently parting a few strands of
nesting material, noticed a tiny patch of distinct orange fur of a hibernating Dormouse. With minimal
disturbance, I left the nest as it was found.
Having been involved with the National Dormouse Survey since 1995 in this particular wood, I had
come across an hibernation nest only once before, although that particular one had been vacated and
left a more 'cradle' shaped nest with an exit hole. Despite being in the open, it was close to the base
of a clump of alders and so possibly the nest had rolled out from the base. This find was in April (the
first of our monthly checks between April and November) and the dormant Dormouse in the only
occupied nesting box in this batch had presumably come from this very nest.
Dormice hibernate at or near ground level in coppiced stools, amongst log piles, in tree roots under
moss or decaying leaves, and generally in places remaining cool and stable, where humidity levels
are high. Studies have shown that they arouse periodically during hibernation without leaving the
nest.
I was quite surprised to find an occupied hibernation nest in what would appear to be quite an
exposed position. The wood in this part is fairly open, a good foraging area for Rabbits and the
occasional Badger with many dug up Bluebell bulbs, and so the chances of the nest being dislodged
seemed rather high. And yet, it was amazing just how well camouflaged the tiny nest was amongst
the fallen leaves. If trodden on by man or beast, I doubt whether the animal within would be damaged
because of the padding from the fibrous nesting material surrounding it and its position level with
the woodland floor. I regularly walk through this wood but had difficulty refinding the nest a week
later to take photographs of it in situ. It was remarkable how much the Bluebell leaves had grown:
one clump had actually grown up though the side of the nest.
Robin Cottrill, Bob Ward and myself arc undertaking a long-term survey of the above woodland, at
present monitoring 53 boxes. We plan to put up more nest boxes in spring 2000 in other parts of the
wood, plus another batch amongst trees and bushes bordering a brook which connects it to another
wood approximately half a kilometre away. This is to try and ascertain whether there is any movement
between the two woods; if this potential link is not being used by Dormice, it could be thickened up
with hedging, with permission from the owners, to provide a valuable wildlife corridor.
Essex Naturalist (New Series) 17 (2000)