The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Although it is found throughout most of Europe it is absent from the Netherlands and is highly endangered in Germany. The estimated population is 70,000 in England, 17,500 in Scotland and 12,500 in Wales (Harris et al ., 1995). The NBMP surveys report an increasing trend in the last 10 years (NBMP, 2008).
In Cornwall it is widespread and infrequent. An increase in 1km squares where this bat is recorded from 25 to 39 since the last edition of this book is not likely to be significant due to the limitations and variables mentioned in the Introduction. Indeed a study carried out by members of the Cornwall Bat Group in 2000 revisiting historically recorded Natterer' s maternity roosts, found the species to be declining in the county. Eleven roosts were surveyed and 10 were still extant. However, the number of bats counted in each roost had declined significantly in all bar one roost. The total number of bats counted in these roosts in 2000 was 380 compared to 602 from historical records. So the indications are that the
Cornish population may not be following the positive trend recorded on a national basis.
Habitat & Ecology
Hunts in woodland and parkland, woodland edge, hedgerows and near water. Roosts in buildings, often older stone-built ones or hollow trees in summer and hibernates in various underground sites in winter.
See Introduction. Loss of mature trees and loss or conversion of heavily timbered barns, churches and farm houses. Loss of habitat quality important for foraging.
Extensive legal protection detailed in Introduction. Low risk of extinction worldwide (IUCN status, 2001). In Cornwall it would be informative to repeat the survey carried out in 2000 to ascertain whether the apparent decline detected is confirmed and if so an action plan to halt this would need to be formed.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.