'Bat Blitz' nets biologists on night hunt
Misunderstood mammals provide clues to habitat health
By Marsha Walton
A sample is taken from a bat's wing to be processed for DNA. The information is used for evolutionary studies.
|There are more than 1,100 bat species. |
They make up almost a quarter of all mammal species.
Bats are not rodents but belong to a group called Chiroptera, which means "hand wing."
Seventy percent of bats eat insects.
The common little brown bat can live more than 32 years.
A single brown bat can catch 1,200 insects in an hour.
More than 50 percent of American bat species are in severe decline or are already listed as endangered.
PEE DEE NATIONAL WILDLIFE REFUGE, North Carolina (CNN) -- The temperature crept above 90 degrees as mosquitoes and fire ants swarmed.
The scene was routine for 42 bat biologists taking part in "Bat Blitz 2004" in central North Carolina. They were studying the intriguing though often misunderstood mammals.
In three nights, the scientists caught 77 bats in mist nets set up in about a dozen locations in the wildlife refuge and Uwharrie National Forest. Among those, five different species were caught, examined and released.
"Nearly a quarter of the mammals on this Earth are bats, and we still know very little about them," said Matina Kalcounis-Rueppell, biology professor at the University of North Carolina at Greensboro.
"There are over a thousand species. They're nocturnal, and they're just doing things that we can't see, and what we can't see or hear, we don't understand," she said.
Each night the scientists and several dozen volunteers packed up bat detectors, nets, lights, kits for processing hair and skin samples, and plenty of insect repellent. At dusk, several mist nets were set up at each location, usually near or over water.
The bat detectors helped researchers "hear" the high-pitched sounds the animals make.
Bats use a type of radar, known as echolocation, for navigating and finding their food. They make high frequency calls out of their mouths or noses and then listen for echoes from insects or objects around them.
Kalcounis-Rueppell said bats' echolocation calls are distinctive and that researchers can often determine what species of bat is flying by without having to catch the animal. After recording a few seconds of the bat calls on the small portable detectors, the sounds were downloaded to laptops for identification.
"Much of what we understand about bats involves technology," said Joe Szewczak, professor at Humboldt State University in California. "Much of what they do is beyond our own senses, so we have to use various bits of technology to see them in the dark, to listen to the sounds we can't hear."
Szewczak also has used tiny radio transmitters that weigh less than a gram to track the animals where they live. He has been awarded a three-year, $673,000 federal grant to develop methods of echolocation analysis. The goal is to find ways of reducing the costs of monitoring threatened and endangered species.
After the bats flew into the nets, they were quickly removed and examined for about 35 minutes. Researchers recorded species, sex, age, weight and measurements and collected hair, skin and fecal samples.
It was a somewhat stressful period for each bat.
"If we could translate, I'm sure it would be bat profanity," said Tim Carter, biology professor from Southern Illinois University as he weighed a feisty red bat he had put in a small bag.
Hair samples will be studied to detect traces of chemicals that may be found in the insects they eat. Cells from the wing are collected for DNA and evolutionary studies. Fecal samples can show what the bats are eating.
Along with scientists from 12 states, dozens of volunteers spent their own money to travel to the forest to help with the bat collection and processing.
"I drove 13 hours straight from Lansing, Michigan, to get here," said Trixi Smith, a Web librarian who attended a bat conservation workshop this year in Arizona to learn how to handle the animals.
"It's really important conservation information. I like being a part of that," she said. "I love being outdoors and working with the animals. And bats are probably one of the most fascinating animals that I've had experience with."
The data collected during Bat Blitz will be used by the U.S. Forest Service and will be made available to other biologists.
"It's a part of the state where we don't have very much information at all on bats," said Mae Lee Hafer, wildlife manager for national forests in North Carolina. "So we're just happy to gather some baseline information as to what bats we have there, so we can better manage our land and possibly enhance our habitat for bats."
Pee Dee National Wildlife Refuge, an 8,500-acre protected area, provides food, shelter and sanctuary for migrating waterfowl.
Because so little is known about bats, their lives and habits are full of misconceptions.
"When you do see a bat up close, they're as beautiful as any other mammal that we think of as attractive or cuddly," Kalcounis-Rueppell said. "They have beautiful faces, coloring, and there's something about them living in a different world at night. It's just exciting to work with them."
The Bat Blitz netted animals from five species: red, Seminole, east pipistrelle, evening and big brown bats.