Leisler’s Bat is the smaller relative of the Noctule Bat. Like the Noctule, Leisler’s Bat appears early in the evening, often before sunset. Flight is usually fast at or just below the level of tree tops. Echolocation calls peak around 25kHz, which means that they are usually slightly higher-pitched than Noctule calls. Despite these differences it can be easy to confuse the two species. Although widespread throughout Britain and Ireland, Leisler’s Bat has a rather disjunct distribution. It can be quite common in some areas, yet rare or unknown nearby. In Yorkshire it is largely a West Yorkshire species. For example, it is quite common in Castleford and Wakefield yet virtually absent a few miles away in North Yorkshire. North Yorkshire records are mostly confined to the extreme south of the county, with very few records elsewhere. Unlike most bats it seems quite tolerant of light and will forage around white street and security lights that attract large insects.
