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By Dan Rudy 

Stats released for 2015 bat driving survey

 

Submitted Illustration

This map shows plot points collected during Wrangell's 2015 bat drive survey. Forty-five individual bats of four different species were registered by volunteers using a car-mounted acoustic monitor, with the greatest activity at the road nearest Earl West Cove.

Results from last summer's citizen science bat tracking program were presented at the Nolan Center on Monday.

Since 2004 the Alaska Department of Fish and Game (ADFG) has been tracking the region's bat population. One component of this research has been the trapping and radiotagging of little brown bats, one of the state's seven identified species. The department also makes use of year-round acoustic monitoring stations and has begun to enlist volunteers to use acoustic driving transects.

This latter approach has volunteers attach the device to their vehicles in order to periodically monitor bat populations along set routes. Driving at 20 miles per hour 45 minutes after sundown on a rainless evening, the roof-mounted microphones pick up the echolocational cries of bats, which are then recorded for later identification. This is possible because different species of bats emit particular, distinguishable calls.

Regional wildlife biologist for ADFG Karen Blejwas explained the mobile monitoring actually works better than static stations because individual bats are less likely to be counted multiple times.

"Those are particularly valuable because it's really hard to understand what trends for that population might be," she said. "They really give us a broader detection than our stationary devices do."

Launched as a pilot program in 2014, last year the vehicular monitoring extended from Gustavus and Haines to include Wrangell, Petersburg, Juneau and Sitka. Presenting the results on Monday, biologist Steve Lewis explained that 50 volunteers – 14 in Wrangell – spent time driving their routes between April and September for a total of 39 surveys. Wrangell bat watchers conducted eight surveys, which registered 45 calls from four species.

"It was really successful. We got some great data," said Blejwas.

The data being collected helps ADFG with its task of wildlife management. Since the collection began, two previously unidentified species were observed in the state, the Yuma miotis and hoary bats.

"We still aren't sure what the northern distribution of these species are," Blejwas added.

"Another couple years of data would be really useful," Lewis said.

The information will also help researchers better understand when bats enter hibernation in the fall and emerge in the spring, the timing of reproduction and migration, and estimated population densities. The data collected goes toward informing population management decisions, including disease control. Lewis pointed out the tracking program will be crucial in determining whether white-nose syndrome has reached Alaska's bat population.

The syndrome is a fungal infection which disturbs bats during their lengthy hibernation periods.

"Every little bit of fat they put on during the summer they need for hibernation," Lewis explained. Ultimately, the condition interrupts their slumber, makes them restless in their hibernacula- their winter abode-and causes them to starve.

East Coast bats tend to spend winters holed up in large groups, and the fungus has resulted in 100 percent mortality for some hibernacula.

White-nose syndrome was first identified a decade ago on species in New York, and the infection spread to populations across the East Coast. Spreading only as far as Nebraska, the condition has suddenly become a concern in western states after turning up on a bat in Washington last month.

"That's really bad news," Lewis commented. "We don't know how that happened."

Dan Rudy/ Wrangell Sentinel

Forest Service interpreter Corree Delabrue shows participants of Monday's bat talk how an acoustic monitor can distinguish between bat species.

This coming year the acoustic transect route in Wrangell will be extended to continue into town, broadening the study's scope as well as making it more convenient for volunteers. While libraries have aided the program by checking out recorder devices to participating communities, in Wrangell the monitor is available through the Wrangell Ranger District office. Those interested in participating are invited to contact Corree Delabrue at 874-2323.

Another way to help is to report sick or dead bats upon discovery, which can then be examined and tested for rabies, white-nose syndrome or other ailments. After finding one, contact the ADFG Diversity Program or local office for further instructions.

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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