The Isles of Scilly Biodiversity Audit 2008 - Cornwall Wildlife Trust

2.2.1.32 Terrestrial MammalsOverviewThe terrestrial mammals include rodents, bats andlarger species, such as deer.Generally speaking mammals are ubiquitous inBritain, but the isolation of the Isles of Scilly meansthat the number of terrestrial mammals that have beenrecorded there is very small (only 10 are certain) andsome of those have been introduced.However, there are at least four species of batsrecorded for the islands, two of which (commonand soprano pipistrelle Pipistrellus pipistrellus and P.pygmaeus) are considered to be resident.Important AreasAmong the small number of terrestrial mammals, onlythe bats are particularly site dependent and coupledwith the fact that they are of conservation concern alltheir breeding and roosting and sites are significant.Conservation ImportanceAll British bat species and their roosts are protectedby the Wildlife and Countryside Act 1981; hedgehogsare also partially protected by this act. Of the eleventerrestrial mammal species in the Isles of Scilly, threeare on the BAP priority list, one of which has beenintroduced. They are:(introduced) West European HedgehogErinaceus europaeusNoctuleNyctalus noctulaSoprano Pipistrelle Pipistrellus pygmaeusThe Scilly shrew Crocidura suaveolens cassiteridum, asubspecies of the Continental lesser white-toothedshrew which is found only in the Isles of Scilly inBritain is significant because of that fact.Trends and IssuesResearchMore research is required in order to fully assessthe status of the various bat species within the Islesof Scilly. In particular, all the nursery roosts andhibernacula need to be identified.Loss of HabitatA number of bat roosting sites and/or hibernaculahave been destroyed in the Isles of Scilly in the past.Nearly all of the destruction has occurred because ofthe demolition or refurbishment of buildings.AgricultureSome agricultural operations, particularly the use ofpesticides, may affect bat populations by reducingtheir food supply – there is evidence of pesticidepoisoning of a single pipistrelle in the past, thoughsome of the chemicals are no longer in use.Public AwarenessAn Isles of Scilly Bat Group which is affiliated to theIoSWT has been set up with the aim of training morelocal people to be bat wardens.Wider public understanding of the small numberof mammals that are found in the Isles of Scilly,including their status and legal protection, would beadvantageous. In particular, the law relating to batsneeds to be widely recognised.Scilly shrew Crocidura suaveolens cassiteridum is a sub-species found only in the Isles of Scilly. Photos: David Mawer and Ben LascellesIsles of Scilly biodiversity audit Page 49