50 The Essex Naturalist
Natterer's bat Myotis nattereri (Kuhl, 1818)
This is a woodland species whose summer roosts in Essex have been found in
older buildings such as churches, (Great Totham, Little Sampford, Great
Horkesley) or barns (Great Totham, Little Hallingbury, Great Henny, Good
Easter).
Additional records have come from hibernation sites with up to 27 found in
the Grays deneholes and 16 near Coggeshall. Wintering individuals have been
found at Great Braxted, Leigh, Warley and Earl's Colne. Laver describes this bat
as common around Colchester and found several hibernating in the brickwork
of wells. Today, it is uncommon and some summer roosts have been lost to barn
conversions, for example at Little Hallingbury and Good Easter.
Daubenton's bat Myotis daubentonii (Kuhl, 1819)
A species that is probably under-recorded in Essex. Summer roosts are often in
trees and only one roost, in a building at Maldon, has been found. This bat is
typically found feeding over open water, where it can be identified with a bat
detector.
Daubenton's bats have been found over lakes at Connaught Water, Great
Myles, Hanningfield Reservoir and Hatfield Forest and, in 1991, one was found
caught on abandoned fishing line by the Stour at Dedham. The major
hibernation site in Essex is at Grays, where up to 58 bats have been found in the
deneholes. There are several autumn records concerning bats found by members
of the public. Three have been found near Colchester High Street, another two
at Lakeside Shopping Centre and others at Burnham and North Fambridge.