A mysterious malady is decimating bat populations across the Northeast and spreading south. The malady, called white-nose syndrome (WNS) because of a white fungus that appears around the muzzle of infected animals, was first documented from Schoharie Cavern, near Albany, N.Y., in 2007. Once word of WNS began to spread, photos from February 2006 showed bats with WNS from Howe Cave, also in New York. By early 2008, WNS had been documented from hibernacula across the Northeast including New York, Vermont, Massachusetts and Connecticut.

Signs of WNS include a white fungus that grows around the muzzle, ears and wing membranes, depleted winter-fat reserves, a lack of immune response during hibernation, scarred wing membranes, difficulty arousing from deep torpor and being active during daylight hours in mid-winter.

To date, species affected by WNS include little brown bat, big brown bat, northern long-eared bat, small-footed bat, eastern pipistrelle and the endangered Indiana bat. Mortality rates in some hibernacula have been greater than 90 percent.

To date, biologists and scientists remain unsure of the causal agent regarding WNS. They cannot be sure whether the fungus causing the white muzzles is the pathogen causing the deaths or whether it is simply a manifest symptom of some other causal agent.

The fungus has been isolated. It is a never-before described psychrophilic fungus closely related to the genus Geomyces. It thrives in cold damp habitats — just the kind you would find in a hibernaculum. It has, in fact, been collected from bats across a widely dispersed range of hibernacula in the Northeast.

While scientists and biologists grapple with the causative agent, WNS appears to be spreading southward. Pennsylvania, New Jersey, Virginia and West Virginia can now be added to the list of states where WNS has been documented.

Some people think of bats as scary things. But a world without bats could, actually, be much scarier. One little brown bat weighing around one ounce can eat up to 1,200 insects per hour. And the little brown is but one of 45 species of bats found in the U.S. In one study, 150 big brown bats surveyed throughout one summer were reported to have eaten enough adult cucumber beetles to prevent the hatching of more than 30 million cucumber beetle larvae.

Bat Conservation International is one of the organizations at the forefront of the WNS battle. To learn the latest regarding WNS visit their Web site at http://www.batcon.org. Besides documentation of the work they are doing, they also have links to other Web sites regarding WNS.