Echolocation
Whiskered bat calls are a series of clicks between about 35 and 90 kHz, sounding loudest at 45 kHz. The clicks are slightly less regular and slower than Daubenton’s bat but heterodyne detectors cannot be relied on to identify to species. Flying in clutter they can be mistaken for pipistrelles, but their frequency range is much wider.
Habits
Whiskered bats favour woodland and riparian habitats, and often fly along woodland paths where they tend to hug the edges and hunt in the denser parts. They also forage in parks, gardens and meadows. Flies are their major prey, but they also take moths, beetles, lacewings, other small insects and spiders, both capturing them in flight and gleaning from vegetation.
In summer they roost in trees and a wide range of building types, including modern ones, but particularly in older stone buildings. They are crevice dwellers, often roosting under hanging tiles or under ridge tiles.
They are regularly found hibernating singly in caves and tunnels, in crevices or sometimes hanging free in the open.
Reproduction and life cycle
Mating takes places in the autumn but has also been observed in all winter months. Females can give birth in their first year but the majority do not do so until their second year. Nursery roosts are sometimes shared with pipistrelles and other species.
Young can fly by three weeks and by six weeks can forage by themselves. Like other Myotis species whiskered bats swarm in and around caves in autumn. This occurs from the beginning of August, earlier than Natterer’s bat. The maximum age recorded is over 23 years.
Distribution, status and conservation
Whiskered bats are widespread in England and Wales, but distribution and population size are uncertain, due to possible confusion with Brandt’s and Alcathoe bats.
In Kent this species was considered rare. Only one small maternity roost, shared with common pipistrelles, is known within the time period of 2002 to 2012, and only occasionally are whiskered/Brandt’s bats found in hibernation.
However, in the summers of 2009 and 2010, during the BCT Bechstein’s Bat Survey, they were found at 12 sites, and the number of individuals trapped was second only to brown long-eared bats. In all woods the traps were set in cluttered habitat if it could be found. This highlights the importance of retaining dense woodland, rather than the tidy woods which result from the over-management and coppicing that is now so often undertaken in the name of conservation.
Surveys from Kent bat group between 2015 and 2023 show a steady increase in numbers across Kent.
