The aims of the Group
Cambridgeshire bat group is dedicated to the conservation of bats.
Its aims are to educate and raise awareness of bats in Cambridgeshire and to study and monitor bat populations, both locally and nationally. The group initiates its own research projects, as well as organising practical conservation such as making and erecting bat boxes and protecting winter hibernation sites. Cambridgeshire bat group also cares for injured bats and gives advice to those who find bats on their property.
Cambridgeshire's bats
In Cambridgeshire, there are records of 12 of the 16 species of bat known to be resident in Britain. They are:
- Common pipistrelle Pipistrellus pipistrellus
- Soprano pipistrelle Pipistrellus pygmaeus
- Nathusius' pipistrelle Pipistrellus nathusii
- Noctule Nyctalus noctula
- Leisler's Nyctalus leisleri
- Serotine Eptesicus serotinus
- Brown long-eared Plectotus auritus
- Natterer's Myotis nattereri
- Whiskered Myotis mystacinus
- Brandt's Myotis brandii
- Daubenton's Myotis daubentonii
- Barbastelle Barbastella barbastella
The most common and widespread of these in Cambridgeshire are the Common and Soprano Pipistrelles, as is the case nationally. Only a few records of Nathusius' Pipistrelle have been collected by the group.
The noctule is thought to be widespread throughout the county, perhaps partly because it is one of our larger bats and is adapted to foraging in the large open fields and fens that dominate the countryside. Cambridgeshire also boasts one of the largest known noctule roosts in the country; approximately 150 bats roost in an office building (this species is more commonly found roosting in trees). Leisler's bat is considered very scarce in Cambridgeshire, with only four records of roosts. There are more records of Leisler's from Suffolk, particularly in and around Thetford.
The serotine is considered uncommon in Cambridgeshire, and it is at the northern limits of its range here. This is reflected in the distribution of known roost sites; they are almost entirely from the south of the county.
Brown long-eared bats are the second most frequently encountered species in buildings in Cambridgeshire. It can be under-recorded on bat detectors because of it's quiet echolocation calls.
Of the Myotis bats, Daubenton's is likely to be the most common, based on bat detector records and numbers encountered on hibernation surveys. However, Natterer's bat is the most frequently found in summer roost sites. Almost half the roost records for Natterer's in Cambridgeshire are in churches. Whiskered and Brandt's bats are very difficult to distinguish and records for these are grouped together. Only a very small number of whiskered/Brandt's roosts are known Cambridgeshire.
Recent radio-tracking work in Cambridgeshire has revealed much information about the roosting and foraging habits of Barbastelles (nationally, a rare species). Please check out the 'Research' page for more information.
The other bats
Bechstein's bat (Myotis bechsteinii) is a rare species, but may be more common and/or widespread than we understand it to be. This is because this species likes to roost in old trees and mature woodland, and such roosts are very difficult to find, and also because they echolocate very quietly and so would usually not be heard on a bat detector. An additional problem is that most of the Myotis bats sound very similar on the bat detector and can be very difficult to distinguish.
The greater horseshoe bat (Rhinolophus ferremequinum) is now restricted to south west England and south Wales and the lesser horseshoe bat (Rhinopholus hipposideros) is restricted to south west England, Wales and west Ireland.
The fourth species not recorded in Cambridgeshire is the grey long-eared bat (Plecotus austriacus) and this species is restricted to the south coast of England and the Isle of Wight.
A seventeenth species?
The greater mouse-eared bat (Myotis myotis) was declared extinct in Britain in 1990. However, in the last few years two greater mouse-eared bats have been found; in 2001 an elderly female was found in Bognor which died a few days after her discovery, and then a young male was found hibernating in a tunnel in Sussex in 2002. Surveys are being carried out to try to determine whether this species is still breeding in Britain.
