Whiskered and Brandt’s bats were only separated as distinct species in 1970 and identification is still problematic. The main visible distinguishing feature is the teeth, with the Whiskered Bat having no clear cusp on the upper premolar (see also Brandt’s Bat). A secondary distinguishing feature for males is that the penis is straight-sided compared to the usually bulbous penis of Brandt’s Bat. Echolocation calls are very similar. As a result of identification difficulties the number of confirmed records of both species is small, with most bats being recorded as Whiskered / Brandt’s. Recently it has become possible to obtain an identification to species level by carrying out DNA tests on bat droppings collected from roosts. The distribution map shows an even, but very thin spread of Whiskered Bat records across North Yorkshire. There are slightly more confirmed Whiskered Bat records than those for Brandt’s. Bat detectors used during surveys frequently detect Whiskered / Brandt’s bats, though usually in small numbers.