Regional bat research wraps up

By SANDY LONG

UPPER DELAWARE REGION — As migratory bats throughout the region begin to move on, a two-year study devoted to their ongoing welfare is being finalized. Mist nets and acoustic monitoring devices are being retired after their use in capturing bats and collecting data as part of the Targeted Mammal Inventory for the Upper Delaware Scenic and Recreational River (UDSRR), which runs approximately 70 miles from Millrift, PA to Hancock, NY.

The inventory supports a broader effort to catalogue the nation’s natural resources throughout its system of 270 national parks. The three-part study has concentrated on small- and medium-sized mammals during phase one and large mammals during phase two. The third component is focused on bats. Each has been conducted by East Stroudsburg University for the National Park Service (NPS).

The information gleaned is intended to improve resource management and to guide the development of public policy to better protect the nation’s natural resources. The primary purpose is to collect baseline data against which future changes or threats can be measured.

The bat study formally began in 2008 using a combination of acoustic detection and mist-net capture to document species present in the corridor, according to Shannon Williams, team leader of the study. “We use a combination of techniques because some bat species are not easy to catch in mist nets, and others are hard to tell apart acoustically from each other,” said Williams. “Capturing bats allows us to assess their health, reproductive condition and age so we know if they are successfully raising young in the area.”

She has been assisted by Jessica Newbern and Sarah Brownlee, as well as NPS natural resource specialist Don Hamilton. Newbern is also conducting a dietary analysis of three migratory species (the silverhaired bat, the hoary bat and the red bat). “There has been little data on the diet of these bats, especially in Pennsylvania, and it will be a valuable asset when biologists are trying to design management plans for these species,” noted Williams.

The women collect data on species, sex, age and reproductive condition, measure body parts, take photographs and gather parasites like bat fleas. They also collect urine and fecal pellets, as well as tissue, hair and cheek cell samples for DNA/RNA studies.

“Analyzing the DNA of bats may allow biologists to see what is going on with bat populations by the variation, or lack thereof, in genetic markers,” explained Williams. “This might show if there has been a dramatic population decline because of the White Nose fungus. The genetic data can also be used to assess the net populations of bats, since this can be difficult due to their secretive nature.”

First documented near Albany, NY in 2007, White Nose Syndrome (WNS) has since caused the deaths of hundreds of thousands of bats in states ranging from Vermont to Virginia. Bats with WNS display characteristic rings of white fungus around their muzzles and on other areas of their bodies. It remains unclear whether the fungus is the cause of death, or a related symptom.

“We check each bat for possible signs of damage on the wings, tail membrane, ears and forearms,” said Williams. “Extensive scarring could be a sign that the bats have been hibernating in a white nose-infected area.”

Williams will also use the data to assess activity levels in the different habitats and compare this year’s levels to last year’s to see if there has been a change that may be caused by white nose syndrome deaths. “This would be a very tentative conclusion as it would be hard to prove it was the only cause of activity change,” she noted.

A few of the things she will look at include the relative abundance of various bat species throughout the summer, reproductive cycles, the times at which different bat species are active at night and which habitats each bat species is using in the corridor. The data can then be used to make suggestions on habitat management within the Upper Delaware River corridor.

Williams noted that one of the study’s most surprising results was the capture of an Eastern small-footed bat near the Zane Grey Museum in Lackawaxen, PA. “The species is state-threatened and uncommon in most areas,” noted Williams. Another interesting find was the capture of the high-flying hoary bat at Stalker, PA, which turned out to be one of the project’s most diverse sites.

Full results of the study will be compiled over the winter and provided to the NPS. For additional information contact Hamilton at Don_Hamilton@nps.gov or 570/729-7842.

The U.S. Fish and Wildlife Service presented a plan to manage the national response to WNS on September 13. Visit www.fws.gov/northeast/white_nose.html for more information. The Pennsylvania Game Commission offers information about bats on its website at pgc.state.pa.us where sightings of diseased or dead bats can also be reported.