Nick is a Freelance Ecologist, working on a wide range of research and survey projects. He led work that selected the six wildcat priority areas for Scottish Wildcat Action and is lead Editor of the forthcoming Mammal Atlas of North-East Scotland and the Cairngorms.
Latest News - Thinking inside the box - camera trapping Scottish wildcat prey
Many of us have embraced camera trapping in recent years - but how many wild mammals are we missing? The surge in mass camera trap development was spurred by demands from hunters for cameras to locate game. Naturally, then, most camera traps are designed for detecting large mammals. However, in the UK and elsewhere, naturalists use them for smaller creatures such as Badgers, Pine Martens and, of course, cats.
But how about going smaller still? Can camera traps be used for detecting, recording and monitoring the smallest of animals, especially rodents and shrews? These are among our most abundant mammals and are vitally important as prey items for predators, including Wildcats.
Photo: Field Vole
Over the last few years, we have developed and trialled techniques for doing just this. It is fair to say that it has revolutionised our own mammal recording activities.
It began at a local Scottish Wildlife Trust nature reserve, where my wife, Rose Toney, and I are voluntary Reserve Convenors. We visit regularly to assist with management and monitoring. We’d added a good range of mammals to the reserve list through regular visits and, especially, by camera trapping. We knew, though, that there must be a range of small mammals that we were missing. We were reluctant to commit to regular live trapping, as it is labour-intensive and, even when carried out carefully, can cause some animal mortality. Therefore, we set about devising a method to detect these small mammals with our camera traps.
We copied the basic live-trapping technique of attracting animals into a baited tunnel and then attached a camera trap to one end. However, there were limitations to address, including the fixed focus of most camera traps. We overcame this initially by using a reading glass lens (don’t dismantle your granny’s glasses without asking) and then graduated to a close-focus filter designed for screwing onto the front of a camera lens. We attached this with blu-tac which worked a treat. We also had to dampen down the infra-red flash to avoid over-illumination and the “white-out” that is familiar to many camera trappers. This was achieved simply by sticking several layers of packing tape over the flash element of the camera. (Note that if your camera has the daylight sensor housed within the flash unit, you will need to leave a tiny hole so that the camera is not fooled into constantly thinking it is night-time.) The tunnel itself evolved through several iterations from a piece of drainpipe to a wooden box with a clear plastic lid (to allow in daylight) and with a pit in the base to hold the bait in the optimum place. Baited with bird seed and dried mealworms, the whole set-up is left out for a few days in likely small mammal places.
Photo: Water Shrew
The results have been astounding. By good fortune, our development of this technique coincided with fieldwork for a soon-to-be-published Mammal Atlas for North-East Scotland and the Cairngorms. As we fine-tuned the design, we were able to add a large volume of records of common but under-recorded species to this project. Back at our nature reserve, we added Wood Mouse, Bank and Field Voles and Common, Pygmy and Water Shrews to the reserve list. Elsewhere we have recorded Brown Rats, Water Voles and both squirrel species so, among mainland Scotland’s rodents and shrews, only the House Mouse remains to be “captured”. We get “by-catch” too - Weasels are recorded quite frequently, presumably attracted by mousey smells, and a range of other mammals, such as Pine Martens and Badgers, sometimes stick their noses inside. This year, we’ve even found the boxes to be great for monitoring the breeding success of Water Rails.
The boxes have also proved to be really popular with children. Through her day job as Co-ordinator of the North East Scotland Biodiversity Partnership, Rose has run a number of initiatives to involve primary schools in camera trapping and the children have delighted in finding out what is lurking behind the bike sheds.
Photo: Stack of 60 boxes ready for delivery to Scottish Wildcat Action
Scottish Wildcat Action is now “thinking small” and has embraced the technique with a recent delivery of 60 boxes and lenses. Previous studies have shown Wildcat densities to be higher in prey-rich eastern Scotland than in more rugged regions of western Scotland, so the boxes will be used to assess to what extent cat activity is related to the availability of prey in priority areas.
Small mammal camera trapping is straightforward for staff and volunteers to carry out, safe for the small mammals themselves and makes great use of Scottish Wildcat Action’s existing arsenal of camera traps. We are really looking forward to seeing the results and delighted that what started out simply as a way of increasing a reserve’s mammal list may now help to unlock some of the secrets of the Wildcat’s hunting habits.
All photos copyright Nick Littlewood, Littlewood Ecology
For more information about the project, visit www.scottishwildcataction.org or on Facebook and Twitter @SaveOurWildcats.
Scottish Wildcat Action is the first national project to save the highly endangered Scottish wildcat from extinction. It is a partnership involving over 20 organisations, including, Scottish Natural Heritage, Royal Zoological Society of Scotland (RZSS), Cairngorms National Park Authority, Forestry Commission Scotland, National Museums Scotland, National Trust for Scotland, Royal (Dick) School of Veterinary Studies at the University of Edinburgh, Scottish Gamekeepers’ Association and the Scottish Wildlife Trust. It is funded by Heritage Lottery Fund and Scottish Government, as well as its partners.
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