There were two possible records from Etwall in the 1970s. The first confirmed occurrence in the county was at Calke Park in 2000 when Bill Cove, National Trust’s head warden, found a few individuals foraging in the grounds of the estate. The bats have been recorded annually since then during a few weeks in May-June when they apparently come to feed on cockchafers. Serotines have also subsequently been recorded at Linton and in October 2005 they were also seen at Coton-in the-Elms. It is not yet known where these bats spend the rest of the year or where their roost site is located. Serotines are rather uncommon in the UK, with a distribution mainly confined to southern England.