Importance of amateurs in improving our understanding of dormice

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.

1. nibbled nuts: as the name suggests, Hazel dormice are partial to

   

   Nut nibbled by a dormouse. Note the smooth inner surface of the hole, and the scratches outside the hole.

   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.

2. dormouse boxes: Doug Woods, a keen

   

   A newly installed dormouse box (Chateau Dormouse, as the child who helped make it called it)

   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.

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12 ways to find mammals

Finding mammals can often be hard – many of them are small, or nocturnal, or both. Last week I got to hear the great ecologist and mammal expert Pat Morris speak to the Surrey Mammal Group. He gave a fascinating (if somewhat macabre at times) talk about how to find mammals. You’re probably familiar with many of the techniques he spoke about, but there were perhaps a few less well-known approaches.

1. Look in local newspapers for reports of mammal sightings: Local newspapers are often a good source of information about where unusual wildlife have been spotted. Clippings from papers may also be useful to refer back to in years to come. If you’re interested in getting information about the presence of a particular species in your area, talking to the local rag and getting a story in there asking people to report sightings may be very helpful.
2. Molehill mapping: One of the problems of many survey techniques is that they may reflect where most of your surveyers are active, rather than where the species is most abundant. One way to check you have good coverage of surveyers is to get data on where molehills can be found. As moles are very widely distributed, any gaps in your map are more likely due to lack of surveying, rather than lack of moles, which tells you where you need to do more work.
3. Droppings: not the pleasantest way to survey for mammals, but once you get your eye in, you can get a good idea of who is around. Many books are too squeamish to show useful photos of droppings for identification, but the Mammal Society have an excellent fold-out guide to British mammal tracks and signs, including some lovely drawings of droppings. It’s a handy size and laminated, so easy to take with you when you’re out and about.

   

   Water vole droppings –  a good sign these elusive creatures are around

4. Trails: look out for paths that go beneath low bushes, or up steep hedgebanks – they may well have been made by wildlife (such as badgers, who tend to follow the same route each time). Smaller mammals sometimes create tunnels in long grass. Spotting these trails can then give you an idea of where to search for other signs, such as hairs, pawprints or droppings.
5. Pawprints / hoofprints: pawprints are another good way of telling if a species is around. Look in soft mud, or after snow, and you could find a surprising number. Sometimes it’s possible to tell from the pawprints whether the animal was running or walking at the time.

   

   Fallow(?) deer print

   

   Pawprints from the mammal tunnel

6. Hairs: some mammal hairs (like badgers) are quite distinctive, while others can be differentiated with the help of a microscope. Hair tubes can help to get samples from small mammals, while barbed wire fences are a good place to look for hair from larger creatures.
7. Food remains: It’s sometimes possible to tell what’s eaten something by the food remains. For example, watervoles cut leaves at a neat angle, and often leave short lengths behind uneaten. It’s also possible to tell whether a nut has been nibbled by dormice, other mice, squirrels or bank voles by how the nut has been opened (I must get round to uploading some pictures of this at some point).

   

   Plant nibbled by water vole

8. Traps: trapping using safe traps (eg. longworth traps) is a good way to tell which small mammals are around. Camera traps can also be handy (it’s how we first found out we had hedgehogs and foxes visiting our garden). Watch a video of visitors to our Mammal tunnel with pawprint tracks and camera trap. Also look out for other things which may attract mammals. For example, mice like to shelter beneath left-over roadworks signs and refugia left out for reptiles.

   

   More slow worms under a corrugated tin refuge

    

9. Nest boxes and tubes: Monitoring artificial nest boxes and tubes is another way of finding mammals. This technique is particularly useful for dormice.
10. Dead bodies: Looking out for dead bodies along roads or in old-fashioned cattle grids can give you a good idea of what’s around, and can be used to monitor change in prevalence over time. A bit grim, but not as grim as point 12…
11. Owl pellets: Dissecting owl pellets and identifying the bones is a good way of telling what small mammals are around to be eaten. It’s relatively straight-forward to identify whole skulls, and teeth are useful for distinguishing between small mammal species. But first you have to find your owl pellets, which may be tricky. Local birders may be able to help you with this.
12. Discarded bottles: [warning – don’t read this if you’re squeamish or eating] back in the days when most milk came in glass bottles, a lot were left lying around in hedges, woods and by roads. These glass bottles are very effective traps for small mammals, as they can squeeze in, but the glass sides and angles mean they can’t get back out. As glass stays around for a long-time, there are still lots of bottles out there, many of which are now full of the remains of small mammals that climbed in and couldn’t get back out. Some bottles may have lots of little skeletons in a foul soup of rotted flesh. If you have the stomach for it, identifying these remains can tell you what’s been around since the bottle was discarded. If nothing else, this should serve as a reminder not to drop litter.

I hope this brief summary of Pat’s excellent talk inspires you to get out and about looking for mammals (or signs or mammals). Do you have any other suggestions for approaches to finding mammals?

 

 

Hog watching

The first we knew about our nocturnal visitor was when my infrared motion-triggered camera caught the unmistakeable shape of a hedgehog snuffling on our lawn. We were very excited, having not seen one for years. So, in an effort to encourage it, each night we would put out a bowl of mealworms. The camera was getting regular footage of the hedgehog, and the bowl was emptied each night. Then, as summer progressed and the days got shorter, we would sometimes see the hedgehog munching away, oblivious to the light and us watching through the French window.

Hedgehog eating mealworms

I wanted to find out more about our nocturnal visitor, so I read Pat Morris’ excellent Hedgehog book. He said that research had shown that what people think of as being ‘their’ hedgehog, a regular visitor to their garden, actually is several hedgehogs. So we decided to try the experiment he suggested. By marking our hedgehog with a small dab of paint on his (or her) spines, we would be able to tell if the one we saw the next night was the same. And he was right – the next day it was a different hedgehog munching the mealworms. So we marked that hog in a different place. By the end of that summer we had seen 7 different adult hedgehogs in our garden, much to our surprise.

We were also able to watch a hedgehog courtship (which seems to involve the male pestering the female until she gives in, temporarily distracted from the mealworms). And then 3 little hoglets started appearing with their mother.

Hedgehog and hoglets

Watching the hedgehogs over the course of the summer was a real privilege and joy. They’re surprisingly quick when they hitch up their skirt and run. They can squeeze through unfeasibly small gaps in hedges, and climb better than you’d expect. They’re not the cleverest animals. They love mealworms, but ignore the slugs that climb into their bowl. Their preferred approach to eating the food we leave out is to climb into the bowl with their food, stand on top of it and then wonder where it has all gone.

My top tips for hog watching:

• If you don’t know if you have hedgehogs visiting your garden, look out for hedgehog droppings. Many wildlife books are a bit bashful about putting in photos of droppings, but it’s much easier to tell from a photo than and description or drawing. The Collins Complete Guide to British Animals has a good guide.

• If you have (or can borrow) an infrared motion triggered camera, set it up so it is aimed at wherever the hedgehog is most likely to visit. In our case it was under the bird feeding station, where mealworms sometimes get dropped, and near an ants nest in our lawn.

• If you have hedgehogs visiting, encourage them to come to a part of the garden you can easily see by putting out bowls of food (meal worms – rehydrated if you buy dried, or dog food).

• If you see a hedgehog out in daylight, it might need veterinary attention. The British Hedgehop Preservation Society can provide info about what to do and where to take them.

Related articles

• Our national species is… the hedgehog?! (wildsouthuk.wordpress.com)
• How to make your garden a hedgehog haven (theguardian.com)