Do bats do more than just hang around? [click for larger image]

These Amazing Bats

by: Annette M. Hall

Charming, witty, informative, and knowledgeable are all adjectives that could be used to describe the presentation recently held in Pinecrest by Patricia Winters, President and in-house bat expert for the California Bat Conservation Fund. Attendees to the free Ranger Program: These Amazing Bats, were engaged, entertained and educated on a lot more than bats.

Common Bat Myths:

Growing up with thousands of bats in our attic, I had heard all these supposed facts and many more. On the occasion a bat would get loose in the house, grandma would chase it around with a broom until she either knocked it down or managed to bat it out the door. Little did we know back then just how important bats are to our economy and in maintaining the balance of nature in our community. Scientists are only now beginning to understand just how important bats truly are.

A bat is the only mammal that can fly. Its scientific name is Chiroptera (Ki-ROP-ter-ah), meaning hand-wing. You could say a bat is handy to have hanging around. After all, bats are great for the ecosystem. Most eat tons and tons of harmful insects. Some species help reseed rainforests, while others pollinate plants. The thousand species of bats are divided into two main groups - Megachiroptera (big hand-wing) and Microchiroptera (small hand-wing). We call them megabats and microbats.

Did you know that?

Bats have the largest surface area to body mass of any mammal, and this requires greater energy to maintain body temperatures. Sun-warmed bridges help adult bats to conserve energy and foster development of their young.

Learn More Bat Facts:

Bat Math Activities

Dwindling Bat Populations

Unfortunately, over the last 20 years, approximately eighty percent of the country's bat population has been lost. Some of the main reasons are habitat destruction and vandalism by ignorant humans. Because bats have long been feared as a source of danger and disease, people often think little about destroying their colonies when they are discovered.

An even larger threat to bats has been the swelling use of pesticides in commercial agriculture. Bats feed primarily on insects, which have often been exposed to pesticides. Pesticides then build up in the tissues of the bat, and they sicken and die.

Maintaining local bat populations helps farmers to better control pests who destroy crops and helps keep pesticide use to a minimum. A single bridge can house as many as 1.5 million bats, which in turn can consume 10 to 15 tons of insects in a single night.

As our older Bridges deteriorate and are systematically being replaced with new structures, farmers became concerned that the loss of known bat populations would negatively effect their crops. Working with transportation authorities, thousands of bat populations have been saved with very little added cost to taxpayers. The benefit to both the farmers and area residents is significant.

A new bridge at Santa Clarita, Los Angeles County, replaced a span that had supported up to 3,500 day-roosting bats. The innovative design features a deep, concrete crevice (20 inches deep, 25 millimeters wide, and 75 feet long). The new habitat, which made up only 0.4 percent of the bridge's total cost), is expected to attract more than 3,000 bats and protect them from light and other man-made environmental impacts.

More than 1,500 Mexican free-tailed bats have turned a private bridge in Orange County, California, into a nursery. The problem is that the Hicks Canyon Haul Road Bridge across Santiago Canyon was scheduled for demolition. Now the bats and their home will be spared, reports the Los Angeles Times.

Many homeschooling families around the country have begun to realize the importance of bats and have built bat houses and explored their benefits. One homeschool mom writes:

My daughter reminded me that there is a Popular Mechanics for Kids TV episode on bats. We loved that show! Cheyenne says that if an adult human were to eat like a bat they'd have to consume like 150 hamburgers every night. We calculated that Cheyenne who is 80 pounds would need to eat 56 pounds of food if we're talking 70% of body weight consumed each day.

One of the more humorous examples Pat used to illustrate the popular misconceptions of our winged friends was by likening our fear of their "blood-sucking" to that of their predominant prey: mosquitoes. Unlike the very few bats that actually prey on the blood of mammals, of which none are known to willingly prey on the blood of humans, female mosquitoes in human populated areas (except for Toxorhynchites), survive partially on the blood of humans.

There are only three bat species that feed on blood: The Common Vampire Bat (Desmodus rotundus), the Hairy-legged Vampire Bat (Diphylla ecaudata), and the White-winged Vampire Bat (Diaemus youngi). All three species are native to the Americas, ranging from Mexico to Brazil, Chile, and Argentina. Contrary to popular belief, these bats rarely bite people because they apparently dislike human blood. The saliva of vampire bats contains a substance, draculin, which prevents the victim's blood from clotting. They, therefore, lap blood rather than suck it as most people imagine.

Learn more about Bats

Bat Books Just for the Little Ones

Bats are truly amazing creatures. Most people know what a bat is and what it looks like, yet there are many myths surrounding bats that simply aren't true. Bats are not blind, they are not flying rodents or birds, they will not suck your blood — and most do not have rabies (but do not take this as an excuse to pick one up). Bats won't try to nest in your hair and usually they do not bother people. However, they do have an amazing ability that scientists and the military have been trying to uncover for more than 100 years. They can "see" using sound — this is known as echolocation or biosonar.

How Bats Hear

Bats use their biosonar in a sound or frequency range that humans cannot hear. Human hearing spans from about 200 hertz (or 200 cycles per second) to 20,000 hertz (or 20,000 cycles per second). Bats can hear well into the ultrasonic range or up to roughly 200,000 hertz. Their biosonar operates from about 25,000 to 100,000 hertz, abbreviated as 25 to 100 kilohertz or khz. (thousand hertz).

It may be a good thing that we cannot hear bats because their biosonar can be quite loud. Echolocation calls can range from 100 decibels (or db.) to about 60 db. 100 db. is approximately equivalent to a smoke detector alarm and 60 db. is about the sound level of a human conversation. If you live in the USA, you most likely have little brown bats and big brown bats in your area. Fortunately, scientists have developed an electronic device called a "Bat Detector," that allows humans to discern bat sounds.

A Bat Detector is a simple, handheld device that listens to the frequencies that bats use to hunt and find their way at night. It converts these frequencies to tones and clicks that humans can hear. Think of it as translator. Most Bat Detectors are the size of a pack of cigarettes and have a special microphone that picks up the echolocation calls of bats.

Build a Bat House

The more you learn about bats, the more you will realize just how special and important they are to us. Just one final word of caution: While most bats do not have rabies, if you find one on the ground, do not handle it! Most bats that have been grounded are grounded for a reason and are more likely to have rabies than an otherwise healthy bat. Call your local conservation office.

Have fun learning about bats.

Additional Batty Links

Updated November 12, 2011

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