Spring Search for Small Mammals!

Taken from Flickr.

After surviving the mild (and often stormy) winter, the promise of warmer weather enticed the Worcestershire Mammal Group from their winter slumber.  After a bit of a stretch and a preening of whiskers, the group decided to welcome in the spring season by focusing on some of our most widespread mammals in the country….. small mammals!

Many British mammals can be considered ‘small’, but the term ‘small mammals’ generally refers to land-mammals which have a head and body length less than 130 mm long.  In Britain, this encompasses 11 species from the families rodentia (mice and voles) and insectivora (shrews), including the house mouse (Mus musculus), wood mouse (Apodemus sylvaticus), yellow-necked mouse (Apodemus flavicollis), hazel dormouse (Muscardinus avellanarius), harvest mouse (Micromys minutus), field vole (Microtus agrestis), bank vole (Clethrionomys glareolus), common shrew (Sorex araneus), pygmy shrew (Sorex minutus) and water shrew (Neomys fodiens).

Although these animals can often be seen scurrying across a path, or hanging from the jaws of fluffy (who probably cause it’s demise), the small and secretive nature of these animals makes it very difficult to survey for them.  Live trapping equipment (such as longworth traps) greatly increase the chance of encountering these mammals, and is definitely one of the best ways to find out what small mammals are in an area, and a great way to observe these fascinating animals up close.

The group decided to plan a small study to live-trap and identify small mammals in Trench Wood, a stunning Site of Special Scientific Interest (SSSI) and ancient woodland jointly owned by the Worcestershire Wildlife Trust and Butterfly Conservation.  The woodland is managed for migrant birds and butterflies, but the group wanted to see if the system of rides, tall herbs and grassland areas provided habitats for small mammals!

Credit to Poppy Morris.

Thirty-two Longworth traps were locked open (so nothing could be caught) and baited on the evening of the 7^th of April.  Each trap was baited with fly castors and oats. The casters (fly pupae – often used by fishermen) were popped into the traps in case any shrews were caught. A fistful of hay was also pushed into the traps to ensure the unwilling prisoners were warm.  On the evening of the 8^th of April, traps were set and re-baited.  The traps were placed along one of the rides, mainly out of sight from public, undercover.

Credit to Poppy Morris.

The next day on April 9^th, 16 volunteers met early (8am) to ensure any captured mammals could be released ASAP, to minimize any stress.  Johnny Birks led the group, and systematically check each longworth trap.  Any animals that were present were identified, sexed and those that wanted to have ago at handling them, were provided with guidance on how to handle them safely – both for the mammal and the handler! Johnny demonstrated that if you hold a small mammal to your chest, it apparently calms them!

Credit to Caroline Hornberger.

Overall, the group had great success, with 3 Bank Voles, 11 Wood Mice and 1 feisty Yellow-necked Mouse captured.  Following the event, all records were sent to Worcestershire Biological Records Centre (WBRC).

A good morning was had by all, and a lot of mammaly fun!

Many thanks to the Worcestershire Wildlife Trust for allowing us to survey in their woodland, and to Dominique Cragg for arranging!

Please Note: If you are thinking of using traps too, bear in mind that catching shrews without a license is illegal. Specialist licences are required from the necessary statutory agencies. In our case, the course leader (Johnny Birks) had a licence.