Underappreciated Bats to Appear on Postage Stamps

Aug. 22, 2002 -- Talk about bad press. No mammal on the planet has suffered from an image problem more than the common bat, but the growing awareness of the vital role bats play in maintaining the health of our ecosystem is about to get a little boost.

On Sept. 13, the U.S. Postal Service is scheduled to release four first class stamps with photos of bats. But that won't make up for decades of horror flicks depicting bats as disease carrying varmints that come out at night to terrorize humans.

That phony image has left bats struggling to survive around the world as humans do just about everything they can to wipe them out. More than half of the species found in the United States are listed as endangered, or are in severe decline, according to Bat Conservation International, a Texas-based outfit founded two decades ago by ecologist Merlin Tuttle, the bats' best friend.

Unique and Insect-Eating

Bats are very vulnerable because mothers produce only one pup a year, and they live in huge colonies, so wiping out one habitat can jeopardize thousands of bats.

Tuttle has been studying bats for more than 40 years, and his organization has grown so fast, it now employs 39 biologists and educators, and is supported by 14,000 members in 70 countries.

They want to do more than just polish the image of the bat. They want the rest of us to sit up and take notice of one of the most remarkable families of mammals on the planet. The bat is the only mammal that truly flies, and it eats so many damaging insects — like mosquitoes — that it's a wonder it took the Postal Service 155 years to get with the program.

And creative biologists are figuring out all sorts of ways to employ the rare talents of the bat.

Putting Bats to Use

Francisco J. Vilella, a vertebrae ecologist at Mississippi State University, will spend the next three years gluing tiny radio transmitters to bats in an effort to monitor the environmental health of a pine forest. Bats, like birds, eat a lot of insects. The common brown bat of North America can eat 1,200 mosquitoes an hour. How the bats fare as they hunt their meals should help Vilella determine the extent of biodiversity in the nighttime forest.

Bats are "a good indicator of environmental health" because the insects they feed on are vulnerable to environmental changes, says Vilella, whose work is supported by the Weyerhaeuser Corp.

On the other side of the country, researchers have installed 45 "bat houses" on 10 organic farms throughout central California to see if they can make bats feel at home. Mexican free-tailed bats eat staggering amounts of cutworms and leafhoppers and other pests, so the more bats in the area, the fewer pests. And that means less dependence on pesticides, which is why the Organic Farming Research Foundation is sponsoring this project.

So far, it seems to be working. In just three months, bats have moved into 40 percent of the multi-chambered bat houses. That's significant in light of a University of Arizona report showing that bats save farmers billions of dollars every year in pesticides.

Of course, if you're one of those folks who has suffered through a bat infestation in your home, none of this is likely to change your opinion. They leave droppings, which incidentally are valuable as fertilizer, and they can streak walls with urine, and their squawking can drive one, well, batty.

Bat Facts

But, for the record, Bat Conservation International has collected a few facts they would like to share with us:

Bats use a high frequency sonar system called echolocation which is so effective they can hunt even tiny insects in the dark of night. It allows fishing bats, for example, to detect a minnow's fin as fine as a human hair even if it is just barely sticking out of the water.

Some bats can hear the footsteps of a moth as it inches across the sand.

About 20 million bats live in Texas's Bracken Cave, and they eat about 200 tons of insects a night.

It only takes about 150 bats to protect farmers from 33 million rootworms each summer.

Bats range in size from the world's smallest mammal, the bumblebee bat of Thailand, which weighs less than a penny, to Indonesia's "flying foxes" with a wingspan of nearly six feet.

And all those bugs must be good for them. The little brown bat of North America can live for more than 32 years.

If all of this is disgusting enough to make you reach for a shot of Tequila, you might be interested to know that without bat pollinators, seed production of the Tequila-producing agave plant drops to 1/3000th of normal.

Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.