Order Chiroptera
Bats
are the only mammals that fly. They do this through the use of thin layers of skin that
connect all fingers with the arm, sides, leg and tail. The middle finger is usually the
longest and the thumb is free. The male and female generally look alike, with the young
frequently darker in colour.
Bats utter high-pitched squeaks, sometimes fifty or more per second, which are
inaudible to humans. Aided by their sensitive ears, they hear the echoes of these sounds
as they bounce off insects and nearby obstacles. Using this "radar", bats can
find their prey in the dark and avoid hitting obstructions. Bats are nocturnal animals,
they roost by day, hanging upside down in caves, rock crevices, hollow trees, buildings, or
mine shafts. Some species are solitary, others are colonial. In winter bats either
hibernate, or, like birds, migrate south, with some species both migrating and hibernating.
The diet of bats in eastern North America is exclusively insects, which they capture on
the wing, either in their mouths or in the "dragnet" of their tail membrane.
Females often assemble in "maternity roosts", away from the males before
giving birth to the young, usually one or two, which are born from May to July. Young
babies often cling to their mother when she flies. Later they hang by themselves at their
roost until they are able to fly, which is usually in five to six weeks.
Bats have few natural enemies. Bats are complementary to birds in that birds feed on
the day-flying insects and bats on night-fliers.
Eastern Pipistrelle pipustrellus subflavus
Description:
Size: forearm 1 1/5 in. (3 cm)
Smallest eastern bat. Yellowish-brown to pale brownish, somewhat grizzled, ears and
forearms pinkishbrown contrasting with blackish wing membranes. Fur tri-coloured,
darkish brown at base, then lighter yellowish brown with tips darker, can be seen by
blowing on their fur to separate the hairs. Thumb large, 1/5 the length of forearm.
Habitat:
Arid lowlands to evergreen mountain forests, woods, canyons, cliffs, rocky hillsides,
waterways, and buildings.
Habits:
Comes out early, often before sundown, flight erratic, weak, mothlike, often
undulating. Hibernates in caves, never in clusters.
Reproduction:
Females congregate as do those of other bat species to bring forth single young in late
spring, mating takes place in fall and occasionally in winter.
Range:
Throughout much of northeast US from south Canada to north Virginia and west to
Nebraska.
Silverhaired Bat Lasionycteris noctivagans
Description:
Size: forearm 1 2/3 in (4.2cm)
Medium sized. Brownish to blackish front frosted with silvery - white. Females are
somewhat paler than males. Ears and membrane are black in colour.
Similarities:
Hoary Bat is larger and has a buffy throat.
Habitat:
Lakes and streams in wooded regions, up to evergreens in the mountains.
Habits:
Hangs in hollow trees, under loose bark, amid thick leaves and in buildings. Its flight
is distinctive, fluttery with short sideways turns, sallies and glides. In summer males
are solitary, females are sociable. In winter, many presumably migrate south, whole some
hibernate in buildings.
Range: