Since winter 2006, bats in parts of the northeast have been dying by the thousands. Biologists from state and federal agencies and conservation organizations have been investigating the cause of the die-off, but so far, there are few answers.

White-nose syndrome (WNS), named for the white fungal halo that develops on the muzzles of afflicted bats, was first detected in a cave near Albany, N.Y., in 2006. A spelunker discovered that almost all the bats in that particular hibernation colony had died. Victims of WNS are emaciated; they lack sufficient body mass to survive months of hibernation.

At first it was thought it might be an isolated incident, but last winter dead bats were found in caves and mines in New York, Vermont, Massachusetts and Connecticut. So far, WNS has not been detected in hibernating bats in Pennsylvania or West Virginia, but infected bats have been discovered in a cave just nine miles north of the Pennsylvania/New York border. According to Bat Conservation International, little brown bats are being hit hardest by WNS, but deaths of endangered Indiana bats, northern myotis, eastern small-footed myotis and eastern pipistrelles are also reported.

WNS is estimated to have already killed hundreds of thousands of bats. That translates to a significant impact on populations of flying insects. The U.S. Fish and Wildlife Service reports that one bat eats 50 to 75 percent of its body weight in insects each night during the summer. Losing hundreds of thousands of bats means gaining billions of flying insects.

Whether the fungus causes WNS or is just a symptom is unclear. At a June meeting in Albany, scientists proposed several hypotheses to explain the massive bat die-off. Greg Turner, a Pennsylvania Game Commission biologist who leads the state's WNS field investigation, asked the key question, "Why do bats appear to be starving to death?" The meeting resulted in five avenues of inquiry:

• Are bats unable to put on enough fat in the fall to make it through the winter?

• Bats store fat normally, but is something happens to them in hibernation that causes them to burn fat faster than normal?

• Is the fungus or some other unknown pathogen directly killing bats?

• Are environmental contaminants somehow involved by directly affecting the bats or their food supply?

• Or could it be some combination of these factors?

Whatever the cause of WNS, Turner is certain how it spreads.

"We're about 99 percent sure that bats spread WNS bat-to-bat," Turner said, "because it has appeared in gated hibernacula that haven't been visited by people for years. We also know none of the dead bats in the affected areas had rabies -- they were all tested. After that, nothing is certain."

"We still don't know what causes WNS, where it came from or if we can stop its spread to other states," said Carl Roe, Game Commission executive director. "But the Game Commission is committed to finding answers that will help wildlife managers better understand WNS and find ways to limit is impact."

Unfortunately, that takes time and money. State wildlife agencies are funded by hunting license fees, taxes paid by hunters and leases on State Game Lands, so game species get the most attention, as they should. WNS is another example of why wildlife agencies should receive at least partial public funding. Wildlife belongs to everyone, not just hunters, so everyone should pay for wildlife management. Then when problems such as WNS that affect non-game species arise, wildlife agencies could respond as forcefully as they address problems facing game species.

Another disturbing aspect of WNS is its eerie similarity to "colony collapse disorder," a malady that is killing honey bees in many areas. A recent book, "A Spring without Bees: How Colony Collapse Disorder has Endangered our Food Supply" by Michael Schacker (2008, Lyons Press), makes a compelling case that recent inexplicable desertions of bee hives is linked to a relatively new pesticide similar to DDT.

Could it be that both bats and bees are victims of man-made environmental contaminants? This is why we must be ever vigilant as the chemical industry continues to introduce new contaminants into the environment at alarming rates.