Surveys for mammals such as dormice (Gliridae ssp.), water voles (Arvicola amphibius), otters (Lutra lutra) and red squirrels (Sciurus vulgaris) are not common. If your local planning authority has asked you for a survey for any of these animals, you should contact one of our ecologists to talk about your site and how it could be impacted upon.
Field mouse (Apodemus sylvaticus) caught during a study for dormice.
Each of these mammals presents its own unique constraints to development applications and their surveys can have stringent seasonal restrictions that may present you with considerable site delays if the matter is not addressed as early as possible.
In the case of water voles and otters, clearly you are less likely to put the habitat these species use at any significant risk unless you are looking to develop proximate to the bank of slow moving streams and rivers (even ditches).
Likewise, the distribution and ranges of red squirrels is not broad and being constrained by their presence across large areas of the UK is unlikely. Dormice however, have a much wider distribution across the country, especially in England and Wales. Most surveys that your local planning authority will ask you for in respect to mammal species will either involve trapping, which is seasonal, or will be scoping exercises.
Scoping exercise aim to provide sufficient justification for trapping to be employed, or to provide some scientifically valid study that justifies the lack on any further action. In the case of the latter, this might be the absence of burrows, latrines and footprints, as well as other field signs including e.g. half-eaten vegetation and/or prey remains.