Alaska Fish & Wildlife News
August 2005

Citizen Scientists Contribute
Valuable Data for Biologists

By Riley Woodford
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Observations by citizen scientists of animals such as this loon provide valuable data for biologists monitoring these animals in the Anchorage area. ADF&G photo.

Vanishing and reappearing bats, malformed frogs and declining loons and are just a few of Alaska wildlife mysteries Dave Tessler is investigating with the help of citizen scientists.

Based in Anchorage, Tessler is the regional nongame biologist for Southcentral Alaska. He’s coordinating the Citizen Science program, working with wildlife watchers who are documenting their observations of loons, grebes, bats and wood frogs in Interior and Southcentral Alaska.

“Citizen science is a new approach,” Tessler said. “We’re in serious need of baseline information, and there are people who are interested in helping. We need to cast a larger net, and get more eyes and ears out there.”

There are three main components to the program: The Alaska Wood Frog Monitoring Program, The Alaska Loon and Grebe Watch, and the Alaska Bat Club. Little is known about the distribution of wood frogs or bats in Alaska, and reports of sightings will help scientists better understand the ranges of these animals. This baseline knowledge is essential to understanding how the Alaska populations change over time.

“With citizen scientists participating, we’re going to find out where these critters are, and what their distribution is,” Tessler said. “Then we can monitor their populations and the health of their habitats.”

Wood frogs are the northernmost-ranging frog in the world, and have a unique blood chemistry that allows them to freeze solid during winter.

“We know wood frogs are found north of the Arctic Circle, but not how extensively,” Tessler said. “We know amphibians are declining worldwide, and boreal toads seem to be declining in Southeast Alaska, but because we haven't had good baselines on this stuff, it’s hard to know.”

Tessler is interested in more than just the distribution of the frogs. A number of malformed wood frogs are turning up in Alaska, and he’d like to identify locations that have a high incidence of malformed frogs.

“Frogs are a great bio-indicator of ecosystem or wetland health, and it’s disturbing when amphibians are declining or where you see a high prevalence of malformations,” he said. “We’re sharing the same space, and if something is happening to these other animals, we might have some concern for ourselves.”

Wood frog surveys involve visiting a wetland during the mating season, listening for wood frog calls for three minutes and then filling out some simple data sheets. Tessler said he had a great response to the program this year, and he’s now sitting on a huge stack of data that will soon be analyzed.

In some cases, citizen scientists send in their data with letters thanking Tessler for the opportunity to contribute, such as this comment from Axel Gillam, an 8-year old cub scout in Homer: “I decided to earn my World Conservation Badge, and thought it would be cool to do a presentation about the wood frog survey to my den. My family and I decided to try a pond by our house. Jackpot! The frogs were really singing! It was fun to go and listen to them at night. Mom said she rarely sees me so quiet. Thanks for letting people like me help you.”

The Alaska Bat Club is a program to document bat sightings. The “club” is open to anyone who has seen a bat in Alaska. Tessler is asking people if they see bats or have bats around their property to fill out a form and send it in. The form is available at

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Wood frogs are the northernmost-ranging frog in the world, and have a unique blood chemistry that allows them to freeze solid during winter. ADF&G photo

Although four species of bat have been seen in Southeast Alaska, only one species is found in Southcentral and Interior Alaska, the little brown bat.

“Basically, we’re trying to get better information about the distribution of bats in Southcentral and Interior Alaska,” Tessler said. “There just isn’t much information. Little brown bats have been found as far north as Fairbanks, but the record is real spotty.”

If the basic distribution of bats in Alaska can be established, biologists can then monitor the summertime populations, and see if they expand or decline. There are other questions as well. Bats disappear from Interior and Southcentral Alaska in the fall, and it is not known where they go.

Alaska’s bats hibernate in the winter, but South-central and Interior Alaska are generally considered far too cold, Tessler said. The bats must be migrating, but no one knows where they go - how far south they migrate and where they spend the winter. Bats hibernate in large groups in safe havens called hibernacula. Female bats also congregate together in the spring in maternity colonies after giving birth, and the location of most of these is also a mystery.

“In Southeast we do have some of the hibernacula mapped, and we do know where some bats are spending the winter in Southeast,” he said. “We know more about bats in Southeast than anywhere else in the state, but even that is not much.”

Tessler said that from a conservation standpoint, any time animals concentrate seasonally in one place, they are more vulnerable. The bats may be congregating in caves or abandoned mines, and mines are sometimes sealed off for safety.

“Mines are being closed, and if you sealed a mine that was an important hibernacula you could conceivably take out a number of bats, or eliminate an important place for them,” Tessler said.

The loon watch and grebe watch programs are more involved than simply reporting sightings, and typically involve people who live near lakes with the birds. Tessler is looking for folks to monitor the presence, nesting and productivity of loons and grebes at their local lake. For more information, look at

Anchorage is the only city in North America with breeding populations of common loons and Pacific loons within the city limits. But fewer loons are living and nesting on Anchorage area lakes, raising concerns about these local populations. Increasing human disturbances and recreation on lakes, loss of nesting habitat, reduced food availability, and pollution could all be contributing to these declines.

The Alaska Loon Watch was initiated by Fish and Game in 1985 to assess the distribution and nesting success of loons in Anchorage and to investigate potential problems. The program continues to monitor lakes in the Anchorage area and has expanded to include surveys of lakes in the Matanuska-Susitna River Valley and on the Kenai Peninsula.

The Alaska Citizen Science Program is a partnership of the Alaska Department of Fish and Game, the U.S Fish and Wildlife Service, the Chugach National Forest, The Alaska Zoo and the Alaska Natural Heritage Program. More information on wood frogs is available at, including wood frog sound clips, photos and data sheets. For more information on the entire Citizen Science Program, see

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