Study area
The study area was an area of broadleaved woodland to the North of
Chepstow (Wales, UK; centred on latitude 51.6711, longitude -2.6862) on
the steep sides of the River Wye valley. In the area are several natural
cave formations and man-made openings in the predominantly limestone
rock strata. One of these caves within the woodland (at latitude
51.67216, longitude -2.68493) has a small opening (~ 600
x 500 mm aperture) but extends a considerable distance downward (at
least 50 m). This cave, referred to as “Middle Earth” in the study by
Davison & Thomas (2017), has recently been shown to be a site used for
swarming by multiple species of bats, including several Myotisspecies (personal observations).