The largest of our Pipistrelle species and with quite shaggy fur. The peak frequency of the echolocation call is 39kHz, so it is usually separable from Common Pipistrelle (45kHz) and Soprano Pipistrelle (55kHz) in flight. Once considered a vagrant species, there are now more than 1200 records of Nathusius’ Pipistrelle in the UK. Maternity roosts are known in Northern Ireland, Lincolnshire, Norfolk, Kent and the East Midlands. In North Yorkshire the species has been recorded on a number of occasions along the northern coast and in the Harrogate and York areas. Although some Nathusius’ Pipistrelles are undoubtedly resident, this is a migratory species. There are a good number of records from oil platforms in the North Sea and many records from the Northumberland and North Yorkshire coasts in late summer. Inland, the species is thought to most likely frequent water-bodies in September.