Archive for Thursday, November 17, 2005

Embracing bats in the garden

November 17, 2005


Bats. They conjure up images of moonless nights and howling coyotes, with the unknown waiting to swoop down and peck out your eyes as you turn into the alley.

That's nonsense. The poor, innocent, blind bat is just trying to survive. Bats are a huge asset to a garden and should be revered.

Why are bats such a stupendous inhabitant of the garden? Because they gobble up mosquitoes and other pesky bugs, oftentimes at the rate of 1,200 small-sized insects in one hour. Personally, I am much more fearful of insect-borne diseases like West Nile virus than I am of the misunderstood bat.

Granted, bats are not the most adorable little mammals; they look a little scary with their claw-type hands and arms that appear as though a cape is attached to them. A science fiction writer probably could not have concocted a more terrifying-looking little animal. In fact, bats are such a different and unique breed of species of mammals that scientists have placed them in a category all their own, the Chiroptera, which means hand-wing. There is the Megachiroptera, which is commonly referred to as a flying fox. Then there is the Microchiroptera, the more common bat that is found worldwide.

A colony of bats gets cozy in a Lawrence home. In September, the bats were evicted from the property by Critter Control of Kaw Valley, owned by Todd Olson. Bats are an asset in the garden because they gobble up mosquitoes and other pesky insects.

A colony of bats gets cozy in a Lawrence home. In September, the bats were evicted from the property by Critter Control of Kaw Valley, owned by Todd Olson. Bats are an asset in the garden because they gobble up mosquitoes and other pesky insects.

Todd Olson, owner of Critter Control of Kaw Valley, deals with a lot of bats and tries to explain the fear that surrounds them.

"I believe this is part-myth, part-misinformation regarding the frequency of disease (rabies), plus bats are rarely seen," he says. "People in general are fearful of the unknown-unseen, and when you throw in a few frightening movies, soon you have a 'real' imagined menace to society."

Myths and rumors

Let's debunk some of the myths and rumors that swarm bats. Bat rabies account for approximately one human death a year. The death toll because of rabies contracted from dogs is a far greater threat to humans. There also is no evidence that bats transmit rabies to other animals. Bats are nocturnal; they hunt in the dim hours of sunset and sunrise, which is why they are rarely seen. They use a form of sonar known as echolocation, and they literally hear their way through the world.

Sadly, bats rank as North America's most rapidly declining and endangered land mammals - mostly due to the exaggerated human fear and persecution the bat has had to endure.

Common bats

Big brown bats: The most common bat in this area, averaging between 4-5 inches in length with a wingspan of around 13 inches. Some favorite roosts are attics, barns, bell towers and behind window shutters. They prey on June bugs, stinkbugs, mosquitoes, leafhoppers and cucumber beetles.

Little brown bats: They look much like big brown bats but are smaller, between 3-4 inches in length.

Robert Timm, curator of mammals at the KU Natural History Museum & Biodiversity Research Center, says, "Bats have roamed the skies for 40 to 45 million years and perhaps longer."

It would be a catastrophe to lose these priceless mammals. There are 15 bat species in Kansas, all of which are insectivorous, meaning they only feed on insects. In fact, bats are the primary predators of vast numbers of insects. If we lost the bats, the farmers would lose much of their crops, and it would be much less enjoyable to spend an evening outdoors with the swarms of mosquitoes and other insects.

One of the reasons that the bat population is in such decline is that they usually only breed one offspring annually (which the females then nurse), and they tend to live in large colonies that can be easily wiped out by one calamity.

"Bats are the only flying mammal," Olson says. "The females group together during the summer months to give birth and raise their offspring in nursing colonies. A nursing female bat can identify her pup by voice and then confirm its identity by smell."

Some of the maladies that have caused a decline in the bat population are the decline of the wetlands, which are breeding grounds for insects, the overuse of pesticides by gardeners, and, as Timm says, "Wind generators that are going up in the Flint Hills are extremely harmful to bats. They are killing bats in huge numbers across the country."

Aiding the bats

What can be done to help the bats thrive and continue to be a huge part of the checks and balances in our ecosystem? Gardeners can plant a variety of perennials, herbs and night-blooming flowers to lure insects that, in turn, will attract bats. Try to avoid using pesticides in the garden.

Olson suggests that a "bat-friendly" gardener can install a yard light or light of some kind above the garden to lure insects.

Bats are also drawn to water and in fact need an abundance of it; they are especially vulnerable to dehydration, sometimes losing 30 percent of their body weight in evaporative water loss in a single afternoon. Adding a water feature can be quite a temptation for the bats.

And there's a misconception about bat houses that Timm wants to debunk.

"Bat houses are not effective here in this part of Kansas as our species don't regularly use these types of houses," he says.

Eradicating bats

If you do have a bat colony in your home, Olson stresses that you respect the animals.

"We go to great effort to work around the bat's reproductive cycle," he says. "We do evict the bats from buildings before and after the nursing season, but not during. We inspect buildings, repair a majority of openings and finally evict the bats using one-way doors or bat valves when the time is right. After the eviction is complete we make the final repair to the entry point.

"In Kansas, gray bats are listed as endangered, and pallid bats are on the state's SINC list. SINC is an acronym for 'species in need of conservation.' We believe that we can serve our customers and work in harmony with the bat's life cycle to create a win-win situation."

So gardeners should rejoice at the sight of a bat prowling the property at dusk and hope that there are more just waiting for night to fall.


OldEnuf2BYurDad 12 years, 7 months ago

Although I've seen bats in my area, I've had a bat house up for years that has never been inhabited. I hope this guy is wrong about bats in Kansas not liking bat houses.

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