Eastern Red Bat
One
of the most wide-spread bats of North America, the Eastern red
bat is often overlooked — mistaken for a hardwood leaf hanging
from a tree or brush pile.
Like all bats, the Eastern red bat (Lasiurus borealis) is a
member of the Order Chiroptera, true flying mammals. Wings are
made of a thin membrane, or patagium, with slender hand bones
stretching in flight and folding the wing when at roost.
Although this bat is only four inches long — not including the
two inch tail — and weighs only 0.2-0.5 ounces, it is considered
a large bat. Named for its coloration, it is the only bat with
obvious differences between the male and female; males have a
deep carrot-red coat while females and juveniles have a duller
coat with prevalent white tips. Each individual hair of the red
bat is made of four bands. Males have a base color of dark gray,
a band of yellow followed by a band of carrot-red with a white
band at the tip. Females have a similar arrangement, but the
yellow band is wider and the carrot red is replaced with a
maroon band, giving them a dull chestnut coat. Both sexes have
buffy white patches on the wrist.
Although found throughout the eastern United States, this bat is
common in the Eastern Deciduous Forest. In Oklahoma, it
frequents the eastern half, but has been found as far west as
Texas County in the panhandle. Often seen in forested areas,
this tree-dweller feeds on insects — especially moths — in early
evening. As with other bats, the red bat feeds by way of
echolocation. A high-pitched sound wave is sent out while
feeding and reflects off an object, hopefully an insect. The bat
is able to determine the distance to the insect based on the
amount of time it takes for the sound wave to return. Once the
bat locates its prey, it either catches the insect with an open
mouth, or will use its wings to capture it.
Breeding season for the red bat is in late summer; bats mate
while in flight. Like many other bats, this species has delayed
implantation (the egg isn’t implanted in the uterine wall until
after hibernation). Three to four young are born in the summer
in tree-top roosts. While many other bat species only have one
or two young, the red bat is able to produce more offspring.
Young bats take their first flight three to four weeks after
birth, and are weaned two to three weeks later.
Even though the Eastern red bat is one of the most prevalent bat
species in North America, it isn’t on the top of the food chain.
Owls, hawks, house cats, raccoons, and foxes are major
predators. Another threat to the red bat is the disturbance of
hibernation sites. Although many bats hibernate in caves, the
red bat overwinters in tree tops, in bark crevices, and
sometimes in brush piles. Because a bats’ heart rate drops from
over 400 beats per minute to just 11-25 beats per minute while
in hibernation, it is very stressful to be removed from a deep
sleep, find a new place to hibernate, and go back into
hibernation.