Things to consider when setting a Longworth trap
"So when you’re thinking about setting a longworth trap the sorts of things you need to be considering are the area where you’re going to be working, and if you’re doing this for the mammal societies many mammals survey, then you will be working with a transect which is a survey area along which, in the case of this survey, 100 metre stretch is chosen and you set a trap every 10 metres. In that instance you would mapping that, and setting a grid reference at the start and at the end.
For todays subject I’m just going to be setting them randomly around an area to see what kind of mammals we’re going to be catching, and what we must be aware of is that it is illegal to capture shrews without a license. A license can be obtained from Natural England, Scottish Natural Heritage or the Countryside Commission for Wales. The reason you require a license for trapping shrews is that they are very prone to dying in longworth traps. Now there are a couple of ways round that, you can get longworth traps which have a shrew hole in them, which is a small hole in them which is reinforced through which shrews can fit, but other mammals you are likely to capture can’t get out. To also ensure you have a low number of shrew deaths, you would also want to include a sufficient amount of an insect species such as blowfly larvae or you can even out cat or dog food. The reason for this is that shrews are carnivorous, as opposed to our other small mammals which would happily feast on porridge oats for example, and shrews have a very fast metabolism and need to eat every 2 to 3 hours."