Wildlife Watch

Searching for our small furry creatures

Several times a year conservation officers from Cheshire Wildlife Trust cary out mammal trapping to find out what species of small mammals are present and to assess the size and health of their populations on the Trust's nature reserves. Special Longworth traps are hidden under bushes, in long grass or amongst fallen logs where the tiny creatures may find them as they run around.

The traps are designed not to hurt anything. The tunnel on the left is the entrance: small mammals like narrow gaps. The box to the right is are filled with hay and food to keep captured animals warm and dry until the trap is opened.

The traps are set in the evening, then checked early the next morning and again in late afternoon: we don't want to leave an animal in the trap for too long. This process is repeated for a few days.

Traps are emptied into large plastic bags, this is because some small mammals can move very fast and jump surprisingly well: it is very easy to loose your catch. The clear plastic means it is easy to see what we have caught. The conservation officers never know what they will find! Each creature is identified, weighed, sexed and then released. A tiny bit of fur on their rump is clipped, so if they are caught again they will not be counted twice.

Here are some of the small mammals that may be found on a nature reserve such as Warburton's Wood or Hatchmere.

A Bank Vole has a rounded face, small ears, short tail, and chestnut brown fur. They like to live in woodland and hedgerows. They feed on grasses, herbs and seeds.

The pygmy shrew is tiny, about 8cm from nose to tail tip. All shrews have a very fast metabolism, and need to eat every few hours. They usually eat insects, spiders and worms. To cater for their needs we put blow-fly pupae, which you can see in the bottom right of the photo, in the trap.

Although we rarely see these small mammals they can be present in large numbers, hundreds in a single field or wood. They are secretive because many larger creatures eat them. Stoats, weasels, barn owls, tawny owls and kestrels all depend on mice and voles. This is why it is important there are healthy populations of small mammals: without them the larger animals would starve.