Maine news, sports, weather from Portland Press Herald / Maine Sunday Telegram, Portland, Maine

April 29, 2012

Survey to assess toll taken on Maine's bats

Wildlife biologists throughout the state and the Northeast want to determine the scope of white-nose syndrome.

By Deirdre Fleming dfleming@mainetoday.com
Staff Writer

This summer in Maine and across the Northeast, an all-out effort will begin to survey and try to protect bat populations that were decimated by white-nose bat syndrome this winter.

Maine biologists confirmed in March that the disease now has a foothold here, just as it has throughout the Northeast. And after the disease was found in several more states, federal biologists have little optimism for the future of half of North America's bat species.

"It's not likely we'll see in the Northeast in our lifetime, or our great-grandchildren's lifetime, bat populations at pre-white-nose syndrome levels. We do have sites where there is up to 100 percent mortality. It's disheartening," said Ann Froschauer, spokeswoman for the U.S. Fish and Wildlife Service in Hadley, Mass.

Because so little is known about bats, scientists can't predict the possible impact of the disease, but seeing more insects where bats previously had thrived is one possible result.

The disease that was first documented in bats in New York in 2007 was found this winter in states as far south as Alabama and as far west as Missouri. It is now confirmed in 19 states and four Canadian provinces, and is estimated by the service to have killed 5.5 million bats in North America.

Of the 46 bat species in North America, six are confirmed to have the disease. But with as many as 26 species of bats that hibernate in colonies in caves and mines, the threat of more species contracting the fungus exists.

"Half the species in North America are at risk," Froschauer said.

In Maine this winter, biologists found the first signs the fungus is spreading through the state's bat population. At two of three hibernacula -- the caves where bats hibernate -- state biologists found fewer than five bats, compared to the 70 to 80 that occupied the sites in past winters, said John DePue, Maine's small mammal leader.

"We were kind of expecting low numbers, but maybe not quite that low," DePue said.

And in Acadia National Park, where bats were not known to hibernate, dead bats with the white fungus were found this winter for the first time, Froschauer said.

"I don't think we were surprised. The disease has spread rapidly through the Northeast and in Canada. As a result, we're finding bats in places we didn't know they were," Froschauer said.

State biologists with the Maine Department of Inland Fisheries and Wildlife visited the two known hibernacula sites here March 8 and 16. A third site is documented and was visited, but was not entered because it is believed to be clean of the fungus, and DePue said biologists did not want to spread the disease.

No dead bats were found outside the third cave.

"That's the glimmer of hope," DePue said.

Still, the rate at which the fungus has been killing bats across North America puts the survival of some bat species -- notably the endangered Indiana and gray bats -- in question, Froschauer said. Moreover, there is little known about bats to help guide biologists, Froschauer said.

"We're playing catch-up, so we can better understand their natural history. We don't yet know the future because what we have been seeing has happened on such a compressed time scale. We don't really know why some bats are living and some are not," Froschauer said.

How fewer bats will affect the ecosystem and natural resource industries, such as agriculture, also is an unknown, said Jim Dill, the pest management specialist with the University of Maine Cooperative Extension.

Bats feed on insects, but how much of a dent Maine's bat population has made in decreasing insects on the landscape remains to be seen, Dill said.

(Continued on page 2)

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