31
(There is some overlap in the north of the county with Suffolk
and in the south with Kent.)
The main reason for the paucity of records is that bats
have to be identified in the hand so therefore only by examining
roosts or corpses can records normally be accepted.
The use of mist nets to catch bats was pioneered in Suffolk
(and mentioned in the first edition of the Handbook of British
Mammals). The technique used is to hold a net at 45 and when
a bat flies over it can be caught by flicking the net and
trapping the bat in the mesh. Noctule bats which fly rather
higher than most can be brought down to net level by lobbing
a pebble in their path so as to fall into the net. The bat
swoops to the pebble and can be caught by flicking the net.
Bats have to be removed swiftly before becoming too tangled
and some species suffer from shock if left in the net too long.
The present survey which has at present been based near Woodham
Ferrers has to date (July 18th) caught 24 bats of which 20
have been Pipistrelles, 3 Serotines and 1 Daubentons. These
make up 5 10km square records or nearly 20% of that done in
the previous twenty years.
Bat Netting. 18.7.81.
To see the above principles in action a field meeting
was organised at Woodham Ferrers on July 18th. The evening
was ideal, with clear skies and a slight northerly breeze.
Twenty intrepid members collected for this meeting and the
first bat (a probable Noctule, flying high and straight through
the trapping area) was seen at 9.30 p.m. The danger of
assuming that every large bat is a Noctule was explained - in
fact Noctules seem to be less broad in the wing than Serotine
(the other large bat) and also appear to fly in rather straighter
lines. Both species fly high, up to about 60ft with frequent
dives. By 9.50 p.m. a group of a least ten Serotine were
feeding over the lake but not flying near the nets. Pipistrelles
were late to emerge but one was caught at about 10.00 p.m. and
everybody was able to have good views of it. The highlight of
the evening came a few minutes later when a Serotine was
caught, and, to the delight of those watching, promptly bit
two members of the Mammal Group sub-committee. A study of food
preferences in bats to find out how selective they are is not
anticipated. After by-elections the light soon faded and the
meeting closed at 10.50 p.m.