Bank Vole

Staff at the Naturetrek office recently carried out a small mammal survey in the nearby woodlands of the Chawton House estate. Our field site consisted of 7.5 acres of ancient woodland surrounded by agricultural fields and grazing pasture. These creatures are important indicator species for the health of an ecosystem, supporting many other species, such as birds of prey, especially Barn Owls.

Our survey found four species: Wood Mouse, Bank Vole, Common Shrew and Yellow-necked Mouse! Our data will be used by the Hampshire Mammal Group as a baseline for the area. Of the 31 individuals we surveyed over three days, around 50% were Wood Mice, which is to be expected as they are the most common small mammal species found in woodlands. Wood Mice are important prey for Tawny Owls, and when woodland rodents’ numbers are low, owls may fail to breed.

Over the UK, several small mammals appear to be affected by changes in agricultural practices. Bank Voles, in particular, are thought to be affected by pesticides. Our results record the presence of Bank Voles in proximity to agricultural fields; evidence Bank Voles are doing well with the current management system in place.

A general UK decline has also been suggested for the Common Shrew. Therefore, all records of this species are useful to help with future conservation decisions. The Yellow-necked Mouse was also an exciting find during our survey, as the species exists in localised, discontinuous populations. They belong to the same genus and have many of the same features as Wood Mice but may be more arboreal in nature.

Small mammal records are generally under-reported and there are insufficient data for ecologists and scientists to see a decline (or increase) in the national population. Armed with an improved understanding of presence and distribution data for small mammals across the UK, researchers will be able to make more reliable conservation decisions for the future.