Residents have been invited to become “citizen scientists” this summer, tracking bats and collecting data for the Alaska Department of Fish and Game (ADFG).
A good-sized group of Wrangellites flocked to the Forest Service’s final chautauqua for the season, where ADFG wildlife biologist Michael Kohan delivered an introductory presentation on our winged mammalian friends.
She is one of two researchers for the program in Southeast, which began in 2011. Several approaches are used to track local bats, gathering data on population as well as new information on area varieties’ habits and social behavior.
“We’ve been doing a bunch of research tagging them in the summer,” Kohan recounted.
Using mist nets set up near forage areas, in trees, over water, and such, bats are caught by researchers. Once caught, researchers determine the sex and species of the specimens, assess wing damage, approximate their age and measure their forearm. Researchers also collect parasites and a small wing sample from each bat, swab it for DNA, then tag the arm and glue a tiny radio tag on its back before setting it free.
A more indirect approach for tracking bat populations is to use passive acoustic monitoring, which records echolocation all night from a single site.
One of the areas explored in their research is where bats live. Kohan explained scientists know females congregate in maternity roosts during the summer in order to have and raise their pups. Throughout the spring, summer and fall, individuals will hole up in day roosts, such as trees, dark spaces outside of houses, snags and the like.
Where Southeast bats roost in the winter—called hibernacula—is still being determined.
“We’re trying to figure that out with more research,” Kohan explained.
More than simple curiosity, where and how bats spend the winter fits into wildlife management strategies. Bat populations east of the Mississippi River are currently being ravaged by white-nose syndrome, a fungal infection that has been making its way westward.
East Coast bats tend to spend winters holed up in large groups, and the fungus has resulted in 100 percent mortality for some hibernacula. Western bats hibernate individually rather than in groups, so Kohan said researchers are hopeful that difference in behavior will mitigate the continued spread of white-nose.
So why is the health of bats important to humans?
As in the case of honey bees, bats are an important component of the ecosystem in ways that are beneficial to human activities. A single little brown bat—the most common species found in Southeast, about the size of a human thumb—eats over 1,000 mosquitoes in an hour. Bats also eat a variety of insects that damage crops, saving about $3 billion for agriculture in the United States.
“They pollinate the plants that produce our food,” Kohan added, and spread seeds over wide areas in more tropical climates.
The citizen science element is a new phase of ADFG’s research that began last summer. With only two researchers in Southeast, the program is reliant on participating residents for support. This approach is doubly useful, collecting data while also changing the sometimes negative public perception of bats.
Using local hubs such as community libraries, tracking equipment and online resources are available for residents to participate in spotting and reporting bat activity.
“The librarians have been an amazing part of how this research is done,” Kohan said. In Wrangell, bat trackers can participate through the local USFS office, facilitated by Cori and Joe Delabrue.
“We’re so into it we decided to take this task on,” Cori explained.
The program is looking for volunteers interested in helping with this summer’s roost count. One method of counting new to Wrangell this summer will be the Bat Driving Survey.
Participants pick a dry night to drive along a predetermined route at a steady speed, about 20 miles per hour. A microphone magnet-mounted on the roof of their car or truck feeds into the “AnaBat” passive detection device, which in turn is equipped with a data card and plugs into a global positioning system device. The volunteers log data onto a sheet and return their gear to the participating library or USFS office the next day.
“We would like to do it two times a month,” Kohan explained, between May and September.
Last year, the survey was conducted in Gustavus and in two routes around Haines. Some 30 volunteers together counted 367 bat calls in 15 surveys, identifying areas of high density. For instance, one “hot spot” identified near Gustavus was near a quarry.
In Wrangell, the proposed route will be from the Zimovia Highway bus turnaround to Fools Thoms Junction. Those interested in making a run can call Cori or Joe Delabrue at the USFS office for more details at 874-2323.
For more information on the research program, its aims and how to help, visit http://www.adfg.alaska.gov/index.cfm?adfg=citizenscience.main.
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