The dormousing year always starts with cleaning out the boxes, and doing any maintenance or replacements needed, ready for when the dormice belatedly emerge from hibernation. Often it’s not the most pleasant of tasks – March can be chilly, and getting rid of manky woodmice nests is never particularly pleasant. This year we were lucky – the weather was pleasant, and the boxes weren’t in too bad condition.
My site is still qutie new, and relatively unscathed by squirrels (who, at some sites, get through large numbers of boxes each year, targeting the glue that holds the layers together of the marine plywood we use). This means there wasn’t too much maintenance to do.
We did have a few old dormice nests to remove. Whereas we’d normally leave the old nests on the ground, this time we bagged them up carefully – I can’t tell you why at the moment, but watch this space… There were also a few beautifully mossy old wren’s nests to remove.
None of the boxes were occupied yet, but hopefully with the lovely weather we’ve been having we might find some dormice in our April check.
It was a relief to be back out in the woods, after the winter break. I know nothing stops me going for walks in the woods in winter, but it’s so nice to be back in the surveying season again.
After last month’s brilliant box check, I was hopeful that we’d see lots of dormice this month. I was expecting the seven youngsters we found in one box to now have separated and set up their own homes nearby. And I was hoping the pinkies would now be bigger and bouncier.
The first set of boxes we surveyed didn’t show new signs of dormouse activity. But, excitingly, there was the start of a new dormouse nest in one of this year’s boxes, in a new bit of the site. This box is one of four in a clump of hazel on the edge of the woods, and separated from the other boxes by a stretch of un-dormousey woodland – tall trees with little understory. It was a bit of an experiment putting the boxes here – I wanted to see if dormice would use this bit of hazel, given the unpromising habitat between it and the rest of the boxes. So far this year, nothing had used any of these boxes. So it was very exciting to see the start of a dormouse nest here.
The shrew who had taken over the bees nest which had taken over a dormouse nest has finally moved out – not before time – the nest was covered in shrew droppings, and sticky from the bees. The kind Dr C volunteered to clean that one out, which is great as it was a health hazard for any creature that might have ventured in.
There was no sign of any of last month’s young in the boxes near where we found the seven dormice. And the bitey adult male has moved out as well. But we did find a 16g young male in a wren’s nest. As I slid the box lid off, and the perspex over the nest, he clambered to the top of the mossy nest, pressing himself against the perspex. He turned out to be a lively little fellow, so I didn’t take a photo of him – I wanted to get him sexed, weighed and back in the nest before he had time to get too upset. This is the first time we’ve found a dormouse in that particular little section of the site, so more encouragement that they’re not limited to one bit of it. And it’s good that he’s probably big enough already to get through the winter.
No sign of last month’s pinkies – hopefully mum has made a nice natural nest for them.
I’m not sure if that’s the last box check I’ll do this year – if the weather stays mild and there’s still food about, dormice could still be active in a month’s time (particularly this year’s young, as they work on fattening up). But if the weather turns cold, we may not find anything. I’d be a bit sad, if that’s the last check of the year, but, sitting beside my first fire of the season, maybe it is time for hibernation.
Apart from the one dormouse, and signs of new nest building, the other thing of note that we found was this rather fine caterpillar. Possibly a pale tussock? What do you think?
I was very excited about this month’s dormouse box check, after the promising signs last month, finding a pregnant dormouse and a young family. I was expecting to find boxes of bouncy young dormice, ready to explode out like jack-in-the-boxes as soon as the lid was removed. But I had forgotten that Sophie, one of the volunteers joining me this month, seems to be cursed, with dormice hiding away from boxes whenever she visits a site, no matter how many dormice are usually found there…
I was reminded of Sophie’s curse early on in the check, when the nest that held the pregnant female last month turned out to be empty, and none of the surrounding boxes had any sign of dormice. Hopefully that means she’s made a natural nest somewhere to have her babies, and we may see them turn up in our boxes next month. But it doesn’t help Sophie get the experience of handling young dormice that she needs to get her license. Still, we knew that one of the last boxes of the check had a family in last month, so we continued with some (slightly diminished) optimism.
The woods are starting to feel autumnal, with the leaves just starting to turn yellow, and fungi everywhere you look.
Luckily we didn’t have to wait until the end of the check to find dormice. A new nest had appeared in a box about halfway through our check route, so we got it off the tree, and had a proper look in. There seemed to be three or four young (eyes open) dormice in the nest. So Sophie started bagging them up for weighing. But it didn’t stop at four. They just kept coming. Five… six… seven. No sign of an adult, but seven healthy, lively youngsters. I’ve no idea how they all fitted in the nest.
Dormice generally have litters of about four, so seven is a big, but not unheard of, number. Most of them were around 8-10g, although one was an impressive 14g (he was also quite feisty, biting Sophie – quite unusual for a dormouse, but perhaps his feisty attitude is how he got so much bigger than his siblings). We used coloured twisty tags to help us keep track of which was which.
We were able to sex a few of them – mostly males, but my personal favourite was a very pretty female with a white tip to her tail. Hopefully, with that distinguishing feature we’ll be able to spot her again next month, and see how she’s doing putting on weight for hibernation.
With seven dormice to go around, we all got a chance to handle a few while putting them back in the box. They were very cooperative, with none trying to escape the nest while we posted their siblings back in. Just as well, as we could have been there all day otherwise…
A few boxes later we found an adult male (who also bit Sophie). By that time we were wondering if she smelt of hazelnut…
A shrew has taken over one of the old bees nests, which they’d taken over from a dormouse nest… It’s funny how some boxes seem to be attractive to several different species, while other nearby boxes are empty.
Our last box of the day also revealed good news – a lactating female, with tiny pinkies (the official term for dormice babies before they develop fur – these were less than 15mm long). We didn’t get them out of the box, and processed mum as quickly as we could (although not before she had bitten me, through the bag!).
With 9 dormice plus pinkies we have well and truly lifted Sophie’s curse. Let’s hope they have a good month feeding, putting on enough weight to see them through the winter… (now there’s an idea!)
As we assembled for this month’s box check I was in two minds about whether to go ahead with it. It was raining, which isn’t ideal, as you don’t want any disturbed dormice getting soggy (their fur isn’t waterproof). And it was quite windy in the car park on top of the ridge of the North Downs. The forecast said it should just be a shower. But the wind was due to double by lunchtime. It’s just not sensible to be in the woods on a windy day.
But the volunteers had travelled to get there (giving up a precious Saturday lie-in). And I would struggle to find time for the check another day this month.
In the end I decided to see what it was like at the site (a 15 minute walk away from the car park, and a bit more sheltered), trusting that the forecast would be right about the shower, and that we’d finish the check before the wind picked up.
Once in the wood, the wind became less noticeable. The leaves were rustling, but the branches were still. So at least it was safe for the volunteers.
We started, as always, with nine boxes we put up last year across the path from the rest. It was where we had found a dormouse last month, so a promising place to start. The dormouse had moved on from last month’s nest. But, a few boxes later, we hit gold.
A lively dormouse jumped out of the box. Once we had bagged it up, it was clear that he was a male in breeding condition. It’s usually quite hard to determine the sex of a dormouse, but that wasn’t a problem with this fellow. While he was safe and dry in a weighing bag I explored the nest for any other occupants, and found a beautiful pregnant female. This was fantastic news – it’s great to see breeding happening on that side of the path. Both dormice safely returned to their nest, we carried on.
Last month we had a couple of bees nests in dormouse boxes. We approached them with caution, watching and listening for any signs of bees. They seemed to have left the first nest, and, as we watched, a shrew emerged from the second. I’m guessing that one no longer has bees in. But we’ll wait til next month to clean it out, to be on the safe side (the bees seem to enjoy lulling you into a false sense of security at my site).
As the check progressed the rain eased up, although by that time most of us had soggy feet.
Dr C checked the last box. Last month it had an empty bluetit nest in it. If it was still disused this month, we’d clean it out, like we had with the other manky bluetit nests. As he slid the lid across, we saw it had been transformed in the last month. No longer a shallow open nest, the box was full of moss (like a wren’s nest), with leaves and honeysuckle bark as well. Although not a classic dormouse nest, we were both suspecting dormice, when a golden face appeared against the perspex.
Dan, a volunteer who is working towards his license, had the job of bagging the dormouse, who turned out to be a lactating mother. In the nest cavity we could feel some young, but, given the less than ideal weather, and their vulnerability, we decided to leave them in the warmth and safety of the nest, and return mum to them as quickly as possible.
It was a wonderful end to the check, and I am very excited to see how they are all getting on next month.
July’s dormouse box check got off to a good start. As I looked into my first box of the day, a lively dormouse appeared.
By the time I had got the box off the tree, into the bag, the dormouse had turned shy, burrowing beneath the nest. The nest itself wasn’t particularly well constructed, so unlikely to survive being lifted out of the box.
Often when active dormice are reluctant to come out of their nests at this time of the year, it’s because they have young they want to protect. So I took things slowly and carefully. Once I had established there were no youngsters in the nest, I had another go at getting out the adult, this time successfully.
It’s always a little nerve-wracking, handling your first active dormouse of the year. The last active one I handled was back in October – 9 months ago. Luckily this one was pretty cooperative (and pretty) so didn’t make a run for freedom up my arms.
We weighed and sexed her quickly, then returned her to the box. She was 16g, which is not unusual for the time of year.
The rest of the check was less exciting – no other dormice and no new dormouse nests. The bees are still occupying a couple of former dormouse nests. The bluetits have all left their nests, but a couple of wrens were still nesting in the cosiest nests imaginable.
The pleasant morning was completed by a quick lap of a Cherry Fair (it’d be rude not to buy some cherries).
Hopefully next month we’ll have some signs of breeding to boost the local dormouse population.
This month’s dormouse box check started early with just Dr C and me. The birds nests were all empty, with the chicks having hatched and fledged between checks. The bees were still occupying a couple of dormouse nests, so we gave them a wide berth. And no dormice to be seen. There wasn’t even any sign of new nesting activities.
So a quiet check. Even the woods seemed relatively subdued after the cacophony of wildflowers on display last month. It was the first check this year without finding any dormice. But a pleasant way to spend a few hours, and good to get a chance to check boxes myself, rather than just map read and supervise. Hopefully next month we will find some dormice, and maybe even some youngsters.
After April’s soggy box check, it came as a relief to set out in the dry in May. The woods were decked out in their best – more species of wildflower than I can name, in all the colours of the rainbow. And the dormice were co-operating too.
The check got off to a good start – in one of the first boxes we checked one of the volunteers called my attention to a small pile of dead leaves at the bottom of the box. That immediately made me think that an apodemus mouse (wood mouse or yellow-necked mouse) had started to build a nest there. That’s not something to particularly get excited about – if an apodemus mouse is using a box, that means it’s one less box available for dormice. And, unlike dormice, they’re not house-proud. They happily urinate and defecate in their nests. And an apodemus mouse is much more likely to bite you than a dormouse is. (Having said that, I’ve never been bitten by an apodemus mouse, but have been bitten twice by dormice…)
So, when I came to have a look at the box, I wasn’t expecting much. There weren’t enough leaves for it to be a proper nest, and there was no structure to it. But I investigated it gently, and as one of the leaves from the top of the pile shifted, I caught a glimpse of gold – the gold of a dormouse, rather than the dull brown of an apodemus.
The dormouse was torpid, so it was an easy job to get the mouse out and weigh it. It was a 16g female, which is about usual for this time of year. We managed to weigh, sex and put the dormouse back in its unconventional nest without waking it, which is always satisfying.
Obviously it’s always a delight to find a dormouse. But this was particularly special, as it’s the first dormouse we’ve found in the new boxes we put up last year. It’s good to know that we work we put in then is now benefiting at least one little dormouse. And it’s also encouraging to know that dormice are active that side of the footpath.
Many of the boxes we checked had birds nests in – mostly bluetit nests, generally with eggs being incubated, although one nest had chicks. They seem to be a little behind compared to previous years. There are also more wren’s nests around this year. Wrens build lovely nests – loads of moss, with a big chamber, and they keep them clean (unlike bluetits). Dormice will quite often move in to these.
We found another dormouse somewhere we weren’t expecting to. At the last few checks a shrew has been using an old dormouse nest, which by now has broken down and got smelly. If it had been unoccupied this month, we’d have cleaned the box out. But a dormouse had moved back in – obviously too lazy to build its own nest. This was a 14g male, who was also torpid, but showed signs of waking, so we dealt with it as quickly as possible before returning it to the dilapidated nest. Hence the lack of photos of this dormouse.
Two of the nicer dormouse nests from previous checks had been taken over by bumblebees. As you probably know, bumblebees are having a tough time at the moment, so it’s hard to begrudge them a couple of nest boxes. But they do pose a hazard for whoever’s checking the nest box, as they are prepared to sting if disturbed. Luckily we escaped unscathed, and will tread cautiously round those boxes until the bees leave the nest (probably in a couple of months time – they go into hibernation even earlier than dormice!).
So, a successful box check this month. Further encouragement that dormice are using the whole box check area, and a reminder to never assume dormice aren’t present in an unlikely looking nest.
I have been meaning for ages to look at how dormice, woodmice and birds used different parts of my site over the course of last year. The burst of energy that spring gives me, and being relatively on top of the gardening, meant I had time on Sunday to play with presenting my data visually. I’ve made a short video to show which boxes were used by what, when.
As you can see, birds dominated the site for the first few months. But quite a few bird nests were subsequently taken over by dormice, once the birds had finished with them. By the end of the year there were an encouraging number of boxes with dormouse nests in.
What do you think of this way of showing the data? What strikes you from it?
It’ll be interesting to look at this year and last year side by side.
One of the advantages of surveying for dormice is that usually the weather’s pretty good. Dormice hibernate all winter, so we don’t check the boxes during the coldest months. And dormice don’t have very waterproof fur, so we don’t tend to check when it’s chucking down with rain, to avoid them getting cold and wet if they get disturbed by us and run up a tree. So yesterday’s check was unusual in its unpleasantness.
The forecast had said that yesterday would be dry and cloudy. The first drops of light rain were falling as we gathered at the meeting point. But not enough to make me think twice about checking – usually the trees provide some cover , so you hardly notice light rain once you’re in the woods.
It’s a bit of a stroll from the meeting point to the start of the site. As we walked, the rain didn’t ease off, but still wasn’t enough to make me consider turning back. As we checked the first ten boxes, the rain got heavier, but we’d come that far already, were armed with an umbrella (for the dormice, not for us – have you tried walking through a wood with a brolly?), and it was cold enough that I was expecting any dormice we found to be torpid, so unlikely to dash up a tree at our approach. I decided that we should continue.
Now the site has 50 boxes up, surveys take a bit longer than usual. We got wetter, and colder, and more dispirited as we went. For the first 25 boxes we found nothing apart from the start of a few bird nests. About halfway through we found a common shrew, which was a brief moment of excitement, but given the weather we didn’t want to disturb it more than necessary, so we moved swiftly on.
Then we got to the few dormice nests we’d left in the boxes from last year. To check them properly we took them off the trees, and, with one person holding a brolly over the bag, someone else had to strip off coats and jumpers to have bare arms for checking the nest (dormice are excellent climbers, and clothing makes it too easy for them to run up an arm). The first nest was empty, but in good condition. The next, where we’d found a dormouse last month, look like it had been flattened by a mouse jumping up and down on it like a trampoline. Nothing in that box.
It wasn’t until we’d got to our 46th box that we finally struck gold. A torpid 16g male dormouse in one of last year’s nests. By that time the rain had almost stopped, and suddenly the whole soggy check seemed worthwhile. If you’ve ever seen any of the ‘making of’ bits at the end of BBC wildlife documentaries, you’ll know that a lot of wildlife watching is about perseverance in the face of uncomfortable conditions. I felt like the team of volunteers who carried out the check yesterday really earned seeing that dormouse. We collected the necessary data as quickly as possible, and tucked the dormouse back up in his nest.
I didn’t take any photos of the check (it wasn’t right weather or light for it), so you’ll have to make do with a photo of last month’s dormouse instead.
My dusters and bag have just about dried out now, and I was very glad of a hot drink and change of clothing when I got home. I woke this morning to glorious sunshine – I picked the wrong day for the box check this month! I must confess, when I heard that the box check this morning at a nearby site had found no dormice, I felt slightly better about my choice of days.
It’s not often that my day job links, even tangentially, with my enthusiasm for wildlife (see this post on the badger cull for a rare exception to this). But I spent the other morning teaching undergraduates the importance of involving patients and the public in clinical trials. As we discussed the different sorts of impact this involvement can have, it reminded me of a recent talk I heard about dormice by Pat Morris.
OK, the link isn’t obvious, but bear with me. Pat Morris is one of the country’s leading experts on dormice. His talk wasn’t so much about the natural history of dormice, as the (surprisingly short) history of the study of hazel dormice. What really struck me was the importance of amateurs in that history.
When Pat turned his attention to hazel dormice (having decided to move on from hedgehogs) very little was known about them. By the early 1980s there were only three scientific papers on hazel dormice. This dearth of knowledge was because they are so difficult to study. They don’t go into traps like other small mammals. And being nocturnal arboreal mammals, you won’t see any if you go out looking for them. So how, apart from chance encounters, could scientists study them?
It was amateur wildlife enthusiasts that discovered two of the key ways that we now use to search for or monitor dormice populations.
nibbled nuts: as the name suggests, Hazel dormice are partial to
hazel nuts. A sharp-eyed amateur noticed that it’s possible to distinguish between a nutshell that’s been opened by a dormouse and one opened by other small mammals (see How to tell who’s been nibbling your nuts). If you can find a nutshell that’s been nibbled by a dormouse, you know there must be dormice present in your wood, even if no-one ever sets eyes on one.
dormouse boxes: Doug Woods, a keen
birder who monitored woodland bird breeding noticed that dormice would sometimes build nests in bird boxes. By adapting bird boxes to discourage birds and encourage dormice (putting the entrance hole at the back of the box, next to the trunk), he developed a monitoring tool that allows us to see and measure dormice.
The amateur contribution to the study of dormice didn’t stop at discovering the research tools. Hundreds of volunteers have helped to collect data about dormice using these tools.
The Great Nut Hunt of 1993 was a pivotal moment in the study of dormice in the UK. Volunteers across the country got on their hands and knees in woodlands, searching for dormouse nibbled nuts. They found 300,000 nuts, which showed that during the 20th century dormice had disappeared from half their range (based on where historical observations had been recorded).
The important contribution of amateurs continues to this day. Many of the people who volunteer to check dormouse boxes each month for the National Dormouse Monitoring Programme are, like me, amateur enthusiasts. The programme now has around 400 sites, and dormice are the only terrestrial mammal being monitored nationally every year in the UK.
This talk encouraged me – even as a volunteer giving a few hours each month, I can help to increase our knowledge about our native wildlife, which will hopefully mean we can get better at protecting it. At work I have seen some striking examples of people who aren’t medical professionals or scientists making vital contributions to our research. It seems to be the same in conservation. We ignore the insight of people with a passion at our peril.
This is my diary of the wildlife where I live in Oxfordshire, and sometimes the places I visit. I am a 14 year old young naturalist with a passion for British wildlife, especially Badgers and Hares. I have been blogging since May 2013 and you can read my old blog posts at www.appletonwildlifediary.blogspot.co.uk