|
Bats create fear
Outdoors
October 26, 2007
In a number of days, folks young and old alike will
be celebrating Halloween. Some will have parties, others visiting
parks in the evening hours, while kids will be trick or treating.
All are part of the tradition of this annual occasion.
But to some, it is also a spooky time of the year.
People will suspend cut-outs of spiders in their windows, or
dangle pictures of bats from their ceilings. The latter is to
be feared because they come out at night, a time that is full
of danger and mystery by humans, and second, they are unsightly
looking creatures. Third, they have been stereotyped because
of the vampire bats.
And even though it is true that vampire bats can
be dangerous because they carry rabies and can pass it on to
their host, people can feel safe in our country, because they
are only found in South and Central America, and there, even
the risks are minimal.
Maybe the way they are seen in their flying pattern,
persons find themselves intimidated by them. But actually, most
bat species are not only harmless, but actually beneficial. Most
people I know would welcome the insectivorous bats for they are
known to eat as many as 1,200 mosquitoes in one hour. Maybe now
we know the reason why those little pests were created
to provide food for these flying mammals. The famous colony of
Mexican free-tail bats that lives underneath the Congress Avenue
Bridge in Austin, Texas, will eat up to 30,000 pounds of insects
in a single night. The same species that has a colony in Bracken
Cave, Texas, containing more than 20 million bats, will eat roughly
20 tons of insects in a single night. These bats, and many other
species, feed on insects that destroy crops, providing an invaluable
service to farmers.
Bats are also beneficial as plant pollinators. Many
species, particularly in the tropical rainforest, feed on plant
nectar, gathering pollen on their bodies as they feed. When they
fly away, they spread the pollen, helping the plant disperse
its seed. Bats are major pollinators of many plants used by humans,
including bananas, figs, mangoes, cashews and agave, which is
used to make tequila.
The feces of bats, called guano, makes a powerful
plant fertilizer. Since it contains nitrogen, this substance
was used to make explosives. Just recently, scientists have discovered
that a number of enzymes found in bat guano work well as cleaning
agents in laundry detergent and other products.
Bats are some of the most amazing animals on Earth.
They are so well adapted to their environment that they have
survived as a group for more than 50 million years, longer than
most other modern animals.
Recently, I touched base with Pamela E. McQuistian,
environmental education specialist for the Department of Conservation
and Natural Resources at Keystone State Park. Since there are
bats living on the grounds near the lake, I knew she could fill
me in as to the residents on the premises.
One of the first questions I addressed was concerning
the bat species that lives in our state. She stated, "There
are nine species of bats that can be found in PA; an additional
two species are found in PA from time to time. Of the nine bats
that can be found here, six hibernate." They include the
following: Little Brown, Keen's Indiana, Small-Footed, Eastern
Pipistrelle, and Big Brown bats. There are three additional that
migrate, I was told. They are the Silver-Haired, Red and Hoary
Bats.
I asked her if the bat box, located on the camping
side of the lake near the handicapped dock, showed evidence of
having bats live in it. She responded, "Each summer, I check
for guano (bat droppings) under our large bat box in the park,
and the accumulated droppings tell me that there are definitely
bats using that box!" she said.
She then detailed their activity.
"The bats that are using the box," McQuistian
explained, "are resting there during the day and then dropping
out to feed over the lake at night. It is not a nursery colony
of female bats with their young we would see many more
bats around the box each dusk if that were the case. These are
probably male bats using the box for shelter."
"Most likely," she continued, "the
bats that are in this bat box are Little Brown Bats and Big Brown
Bats, both of which leave their summer roosts in October to December
(Big Browns are the last to enter hibernation) to seek out caves
or mines to hibernate in for the winter. The environmental
specialist educated me that the Little Brown bats will return
to the park in April or May, and the Big Browns should return
in March or April.
McQuistian concluded by noting that "Many of
the fears people have of bats are unwarranted. They are incredible
animals."
During the summer months, while bats are living
in the park, programs are held at the park whereby people are
invited to walk down to the lake at dusk and watch these mammals
feed over the waters and around the spectators.
Paul j. volkmann
10/11/07
|