Feeling batty?

Scientists want help in studying bats, loons, grebes, wood frogs

Posted: Monday, August 15, 2005

Hate annoying in-sects? Then you ought to love bats because just one of these flying mammals can consume 5,000 bugs in one night, according to studies.

Though five species of bat are known to live in Alaska, little is understood about their habits or the size of their populations. The Alaska Department of Fish and Game wants help in gathering data about the flying, furry creatures.

Fish and Game, in partnership with the U.S. Fish and Wildlife Service, Chugach National Forest, The Alaska Zoo and the Alaska Natural Heritage Program, has launched the Citizen Science Program, linking professional scientists with the private citizen observers who will assist in collecting information to support research and conservation planning.

According to the program Web site, volunteers can be individuals, families, community organizations, school groups — essentially anyone interested in learning more about local wildlife.

There are 40 species of bat in the United States, and more than 1,000 worldwide. They make up almost a quarter of all mammal species and their combined biomass requires a healthy food supply. These insectivores fill a valuable ecological niche that helps keep insect populations under control.

"They filter out the krill of the air," said David Tessler, regional nongame wildlife biologist with Fish and Game.

While scientists may know something about what bats like to eat, they have no idea how big the Alaska population is, what habitats they tend to seek or what environmental pressures they face.

"We can only guess," Tessler said.

Currently, three programs are under way gathering information on wood frogs, loons, grebes, and Alaska bats. For more on the frogs and birds, visit either the Alaska Wood Frog Monitoring Program or Alaska Loon and Grebe Watch Web pages.

For bats, it's the Alaska Bat Monitoring Program. There's even a club, the Alaska Bat Club, with its own Web page. It's not hard to join this club, and, in fact, you already may be a member and not know it. Seen a bat or even just want to? You're in the club.

Among the unknowns surrounding Alaska bats is where they go in the winter. Some species migrate, while others hibernate, some for up to six months a year. Just what Alaska species do and why they do it are open questions.

The little brown bats that frequent Southcentral and Interior Alaska are thought to head to Southeast or even further south following the food supply. That's the kind of information Tessler hopes the citizen program will acquire.

Another open question surrounds the driving force behind migration. Is it instinctual as in birds or something else?

"We have no idea," Tessler said. "We suspect migration evolved for similar reasons as birds, but like birds, species of bat are highly variable. We are pretty sure they must be migrating, but we just don't know."

Bats have been known to hibernate in the attics of cabins where it is cold but not cold enough to kill, Tessler said.

The order name for bats is chiroptera, which literally means "hand-wing," owing to the fact the elongated bones in bats' wings are the same as human arms and fingers with webbing providing the wing surface. Bats are the only mammals that truly fly. Gliding, like so-called "flying squirrels," is a common adaptation in mammals, but it is not flying.

Bats are mostly nocturnal, though they may be seen in daylight in Alaska owing to the long summer days. Contrary to folklore, they are not blind and some kinds of bats actually see quite well. But they "see" at night much more accurately with echolocation — emitting hundreds of high-frequency sound waves per second (usually inaudible to humans) that bounce off prey and obstacles, reflecting back to the bats and painting a picture of their surroundings similar in many ways to radar or sonar.

Bats can avoid obstacles as thin as a human hair and catch speedy insects in total darkness. They are great flyers, though probably not as quick and agile as swallows, which compete for the same food source, Tessler said.

Scientists are interested in bats because many species are in serious trouble worldwide. The U.S. Fish and Wildlife Service listed the entire genera Myotis as a "conservation concern" in 2003. Populations are declining due to human-related factors, according to studies. The mammals have a slow reproduction rate, making them especially vulnerable to rapid declines in numbers.

The general lack of knowledge makes it difficult for scientists to assess how to protect their critical needs. What is known is that in many places habitats are being destroyed by development, deforestation and closure of abandoned mines. Also, increased use of insecticides has, in some places, had a decided impact on food sources.

It is not known if human activity is having the same kind of effects in Alaska, though forest clearing in Southeast may be. Tessler said the Forest Service had been doing a good job in closing abandoned mines in Southeast in a bat-friendly way, leaving access open to the animals.

A total of $35,000 is set aside in the Fish and Game budget for the three information-gathering programs, Tessler said. Those for frogs, loons and grebes have been running longer than the new bat program. While frogs and birds may seem more appealing, Tessler said he is encouraged by the response so far to the bat study program. Folks genuinely seem intrigued, he said.

"There are definitely different audiences. But there are a lot of people out there who care about their surroundings and the animals they share it with. They are eager to help," he said.

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