Alder Kitten is fairly widespread in western Britain, and has good populations in Kent and Norfolk, but is curiously absent from large areas of central Britain. The first Upper Thames record was from Berkshire in June 2023 (not yet mapped), with two individuals trapped on consecutive nights.

There have also been recent records in Hampshire and Surrey, so it seems that this species is expanding its range, although it is too early to know if it is yet breeding in our region.