In the winter of 2007, an extremely large number of bats in New York and Vermont died of an unknown cause. In the previous year alone, between 8,000 and 11,000 bats had died in New York, the largest bat die-off recorded in North American history. One thing most of the affected bats had in common was a white, fuzzy ring around their muzzles, a fungus identified as a member of the genus Fusarium. It is unclear whether the Fusarium infection caused the bat deaths or if it was rather a symptom indicating their illness. One endangered mammal specialist suggested that the Fusarium may be an indication that the bats are too sick to groom themselves as they normally would. The affected bats had used up their energy stores halfway through their hibernation, which might be a clue to the cause of their deaths. They were all located near the entrance of the cave, and many flew out of the cave into snow banks or woodpiles to die. As of spring 2008, four species of bats have been connected with this epidemic – populations of Indiana bats, Eastern pipistrelles, Northern long-eared myotis, and little brown bats.  Since these bats congregate very tightly during hibernation (as many as 300 in one square foot of space), the disease could spread very rapidly. Most bats are migratory, enabling the disease to reach other areas and species, which could pose a serious threat for the agriculture industry. Healthy bats can eat up to half their body weight in insects every night they feed, and many of these insects can be harmful to crops such as wheat and apple. The bats also are responsible for entire ecosystems inside of caves, since they are the ones that bring in nutrients that many other organisms rely on. Please refrain from  contact with bats that are suspected to be infected, decontaminate all clothing and gear used in any New England cave in the last 2 years, and report any dead bats found outside normal hibernation caves in an effort to keep the disease from spreading. The infection is not thought to present any direct threat to humans, but rather humans may spread a possible disease agent to the bats.

--A. Stevens