There are fewer than 50 native species of terrestrial mammal in Great Britain with several introduced species.  Richard Graves Associates can survey and advise on the following:


Bat Bats are the second most diverse group of mammals in the world, with something like 1,100 species currently known, with new ones added on a regular basis. As the British Isles are at the edge of European bat distribution there are just 18 species of bat in the UK, all of which are European Protected Species.  Bats can be found all over the British Isles and are (other than birds) often the most frequently encountered protected species in urban environments. Two species: Pipistrellus pipistrellus common pipistrelle and Pipistrellus pygmaeus soprano pipistrelle are relatively common and ubiquitous; other species are much rarer and may be restricted to certain habitats.  All bats in the British Isles feed on insects and all use ultra-sound to navigate, feed and communicate.  British bats are all relatively small and can fit into small spaces.  Bats naturally roost in caves and trees and may use several different roosts for different purposes during the year.  A bats’ roost is also fully protected.  As suitable trees and caves are no longer common in most landscapes, some species have adapted and now use human built structures such as houses, barns, churches, hospitals and barracks to roost in. Many bat roosts in buildings never attract the attention of the users and may not be obvious.  Bats can roost in roof voids, sometimes in the joists but can also be found using the following features:

  • Soffits
  • Barge boards
  • Roof tiles
  • Hanging tiles
  • Flashings
  • Window frames
  • Cavity walls

If bats are present at your site they will need full consideration as early as possible in design and implementation in order for things to proceed legally.  The following information will be required:

  • Survey, sufficient information about the bat species and population present and their use of the site
  • Roost locations and type, can they be retained in-situ or can they be replaced
  • Foraging and commuting, what features of the site are important for feeding and flying
  • Lighting, as bats are primarily nocturnal they are sensitive to lighting, which may prevent them roosting or feeding
  • Wind farms and turbines, these developments have particular long term impacts on bats and require special consideration
  • Licences for development, in order to allow development affecting bats to proceed legally, a licence may be required from the Statutory Nature Conservation Agency

Richard Graves Associates has many years’ experience of planning and undertaking bat surveys and advising on bats and development, including the development of current bat survey good practice guidance:

We can help with projects from small loft conversion schemes to major infrastructure projects.  Our services include:

  • Bat scoping surveys
  • Building and internal roost inspections
  • Manual activity surveys
  • Automatic detector surveys
  • Bat mitigation design
  • Planning submissions
  • Development licences for bats
  • Bat monitoring


Bats are active between March and October, depending on the location and weather.  It is important to gather as much information as possible during the whole of the active season.


Badger Meles meles the badger is the largest surviving carnivorous species of mammal in the British Isles and is a member of the weasel family.  Badgers live in family groups known as clans and are highly territorial; they construct underground shelters known as setts, which may have several uses.  Clans also tend to remain within a territory for many years.  While it is not always easy to observe the animals themselves in the wild, their distinctive colouration makes them unmistakeable.  Badgers may also leave several field signs, which can enable their importance in the landscape to be assessed.

Badgers are fully protected under their own act, The Protection of Badgers Act 1992.  The purpose of the act was to make illegal the persecution of badgers rather than for nature conservation.  However, despite the purpose, badgers are a material consideration in planning and licences may be required if the animals or their setts are likely to be affected by development.

Richard Graves Associates has many years’ experience of surveying and advising on badgers and provides the following services:

  • Badger survey including location and sett classification
  • Badger advice and licensing (note licences are not normally issued between November and July)
  • Sett monitoring
  • Sett exclusion
  • Advice on replacement sett construction


Survey for field signs of badgers can be undertaken at any time of year but evidence will usually be easier to observe during the winter months.

Riparian Mammals


Otter Lutra lutra European otter is an amphibious carnivorous species that was once common in most of the river systems in the British Isles. The otter suffered from the effects of pollution in our rivers and was hunted to near extinction in most of England and Wales.  Since the 1970s, as rivers have been cleaned up and hunting been banned, otters have returned to their former range and are now present in all counties.  Otters have large home ranges, which may include several kilometres of water courses.  Otters shelter in holts, which may be above or below ground and may have several within a territory. They are highly territorial so only a small number may be present in each catchment.

Otters are a European Protected Species and if present must be considered prior to planning and development.  Richard Graves Associates can provide:

  • Baseline otter surveys
  • Mitigation advice
  • Advice on licencing

Water Vole

Water VoleArvicola amphibius water vole is a medium sized rodent, which inhabits river banks in the UK.  Through a combination of competition from Rattus novegicus brown rat, predation by the introduced Mustela vison American mink and loss of habitat, water vole populations have been drastically reduced over the last 30 years.  As a result of this decline water voles and their habitat are now listed on Schedule 5 of the Wildlife and Countryside Act 1981 (as amended).

Richard Graves Associates can advise on the presence and implications of water voles at your site and provides the following services:

  • Baseline water vole surveys
  • Mitigation and translocation advice
  • Advice on licencing


Evidence of riparian mammals can be observed in the field at any time of year but may be more evident during spring and summer.

Other Protected Mammal Species

Dormouse Several other species of mammal are protected in the UK.  Felis sylvestris wildcat and Muscardinus avellenarius hazel dormouse are both European protected species as are most marine mammals.  Martes martes pine marten and Sciurus vulgaris red squirrel are both protected under the Wildlife and Countryside Act.

Non-native mammals

Many species of mammal have been introduced to the British Isles over the years.  Mus muscualaris house mouse, brown rat and Sciurus carolinensis grey squirrel are well known. Less well known but a problem in some areas are: American mink, Glis glis edible dormouse and Muntiacus reevesi muntjac deer.

Richard Graves Associates can advise you on mammal survey, mitigation, protection and other issues that may arise during the development process.