New York wildlife biologists are still trying to find out what caused the mass die-off of the bat population in eastern New York and parts of New England this past winter.
Bats that survived an affliction dubbed "white-nose syndrome” will soon emerge from hibernation. Tens of thousands of other bats are believed to have died from the ailment.
Wildlife experts with the state Department of Environmental Conservation have been investigating what’s causing the die-off, with help from top research labs around the country.
But pathologists haven’t found any evidence of an underlying virus or bacteria.
Some researchers suspect mild winters may be forcing bats to burn through their fat stores faster. Others fear that increased pesticide use in recent years to combat West Nile virus might be interfering with the bats’ metabolism — or killing off their insect food supply.