There are currently several methods used to survey for hazel dormice including nest tubes, nest boxes, nut searching and nest searching. However, these scarce, arboreal small mammals can be difficult to detect and it is uncertain which method or combination of methods works best in different habitat types. This project compares the existing survey methods with footprint tunnels across a range of sites in Suffolk and is running between April to November.
A day in the life of a dormouse surveyor
We have arrived on site early, as now the clocks have gone back the days are so much shorter. It’s cold, so extra layers are needed, but this also gives protection against prickly vegetation. Our survey site this morning is a relatively young, scrubby habitat, although it is well connected to a wider landscape of ancient hedgerows and small woodlands.
Alison quietly approaches the first survey point where we have a nest box, nest tube and a footprint tunnel – there are 50 of these for each of the twelve study sites. First, she stoppers the nest tube with a sponge bung, then puts a handkerchief in the hole in the rear of the nest box. It’s going to be a long day, so I move onto Point Two without waiting to see whether she has found anything.
I hear the word “Dormouse!”, so I hurry back. The nest tube is now off the tree and within a bag with a perfectly formed, woven nest showing in the rear of the tube. The owner of the nest is looking up at us, beady black eyes in a golden coat ending in a thick furry tail. Alison deftly catches the dormouse, ages and sexes it before weighing. “Juvenile, male, 15 grams – a good weight”. She then ‘posts’ the animal back into its tube and it is returned to the tree. She then checks the box which is empty and slides out the footprint tunnel. There is a myriad of tiny rounded footprints on the white card belonging to wood mice. It’s as though they have been manically dancing through the ink pads. No dormouse prints here though, despite the nest close by.
We get lucky at Point 5 at a particularly prickly area of the site. I tease my hand into the dog rose and grab the footprint tunnel insert and pull. There is a trail of triangular shaped prints running across the card, originating from a dormouse. They have very distinctive pads on both their front and hind feet, probably helping them be such good climbers. We record this, then carefully replace the insert and move on.
Three hours later we have finished and it’s time for a short break. We have had to change nearly all the papers due to high levels of wood mouse activity in the tunnels, even though they are un-baited. We haven’t seen any more dormice, but we have found a couple of nests and about 5 sets of their footprints. This is typical, the evidence of footprints seems to outstrip other forms of evidence.
Then it’s off to the next site. This time it’s a hedgerow next to an arable field which we are grateful has been harvested, as this eases access. We expect to find a nest in Tube 2 which had been built in a previous month, but there is no trace of it now. Further down those tell-tale footprints are found again in a tunnel, the only evidence at this site for this month.
A final surprise
We check the time. The next site is a woodland, but as we have only an hour before the light fails we have to call it a day. There is still the preparation of the card strips for the next day’s surveying – by todays tally of activity in the tunnels we are going to need another 200 of these to complete this week’s survey of six sites. We start to retrace our steps back to the car, but Alison stops. She has spotted a natural dormouse nest in some bramble close to one of our survey points. These nests are much easier to find now the leaves are starting to become sparse. It appears that despite the abundance of nest boxes and tubes along the hedge they still choose to do their own thing!