Distribution and population densities of seven species of bat in northern England

Abstract

Distribution and minimum population densities for seven UK bat species known to be resident in northern England were calculated in an area covering 2500 km2. The species present were pipistrelle (Pipistrellus pipistrellus), brown long‐eared (Plecotus auritus), Daubenton's (Myotis daubentonii), whiskered (Myotis mystacinus), Natterer's (Myotis nattereri), noctule (Nyctalus noctula) and Brandt's (Myotis brandtii). Data were collected primarily from counts at summer roosts over the period 1983 to 1990. A total of 310 bat roosts were discovered within the study area. Of the 256 roosts at which the species present was identified, the majority, 127 (49.6%) were P. pipistrellus, with a mean maternity roost size of 69.6 bats. A minimum population density of 12.6 batskm−2 was estimated for P. pipistrellus, based on summer (maternity) roosts. The minimum population density estimate was higher than previous studies in northern England but substantially lower than those reported in Scotland (18.2 bats km‐−2). The combined density of M. mystacinus, M. brandtii, and P. pipistrellus, which have similar foraging styles (15.8 bats km−2), is comparable to Scottish P. pipistrellus densities. The density of M. duubentonii was also lower than in Scotland, although the density of P. auritus was comparable. The majority of summer roosts for all species were found in buildings, except N. noctula and M. duubentonii which used bridges/tunnels or trees.