Home is a Pine Tree

Indiana Bats prefer to Roost in Yellow Pine Snags

Indiana bat
Indiana bats are small – they weigh about as much as a stack of three pennies. Photo by Caroline Byrne, Center for Bat Research, Outreach, and Conservation.

Every summer, female Indiana bats fly through southern Appalachian forests looking for a place to rear their pups. A new study, coauthored by U.S. Forest Service research ecologist, Susan Loeb, suggests that the bats are looking for yellow pine snags.

Although Indiana bats sometimes roosted in other trees, they strongly preferred yellow pine snags, especially when the snags were taller than the surrounding trees.

“Understanding the summer roost ecology of Indiana bats will help managers develop strategies to protect the species,” says Loeb. “Summer is when females are raising their pups, so it’s an important time.”

The study took place on public lands in the mountains of western North Carolina – the Cherokee National Forest, the Nantahala National Forest, and the Great Smoky Mountains National Park. The study area covered more than 600,000 acres, and the forests were mostly mixed pine-hardwood with a history of frequent fire. Joy O’Keefe, an assistant professor at Indiana State University, led the study, which was published in Forest Ecology and Management.

For five years, Loeb and O’Keefe spent summer nights in the forest, capturing bats.

“We hung mist nets over trails, streams, and forest roads,” says Loeb. “By August 2012, we had captured 50 adult female bats, 3 juveniles, and 7 adult males.”

Loeb and O’Keefe fitted captured bats – especially the adult females – with a small, lightweight radio transmitter to track their movements. The scientists followed the bats to their roosts and then assessed 69 roost trees and the surrounding areas.

snag
In the southern Appalachians, shortleaf pine snags are one of the preferred summer roosts for female Indiana bats. USFS photo.

“Most of the roost trees were yellow pine, such as shortleaf pine,” says Loeb. “Our study shows that in the southern Appalachians, Indiana bats strongly prefer roosting in yellow pine snags.” Snags that were tall and surrounded by other snags were especially popular.

In the midwestern U.S., Indiana bats often stay in a roost tree for long periods of time and sometimes return to the same tree each year. However, Loeb and O’Keefe found that in western North Carolina, bats move from roost to roost every few days.

“Indiana bats appear to have different preferences for tree species in different parts of their range,” says Loeb. “And they have a wide range – they can be found in 22 states throughout the Midwest, Southeast, and Northeast U.S.” Indiana bats are federally endangered, and the southern Appalachians are on the edge of the species’ range.

Managers can help create and maintain Indiana bat habitat by keeping existing snags. Loeb and O’Keefe recommend protecting patches of large snags from the wind by keeping a buffer of live trees around them. Managers can also create conditions that promote future habitat – particularly by using prescribed fire to regenerate pine forests.

“Fire may be necessary for the persistence of yellow pine forests in this region,” says Loeb. “Because yellow pines are important roost types, fire could be a critical management tool for sustaining Indiana bat roosting habitat.”

Read the full text of the article.

For more information, email Susan Loeb at sloeb@fs.fed.us.

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