NJ Bats Being Affected By Mysterious Disease

Several years ago, researchers began to report on a mysterious illness in the Northeast that is killing thousands of hibernating bats.

Wildlife officials are calling the illness “white nose syndrome” because the most obvious symptom is a white fungus that forms around the noses of some, but not all, of the afflicted bats.

Researchers do not yet know if the fungus actually causes death, but they have observed that bats with white nose syndrome deplete their fat reserves months before they would normally emerge from hibernation, and die as a result.

Experts have also advised the public to avoid entering any caves and mines that might harbor bats until more is known about the problem.

At that time, no evidence of disease was found among New Jersey’s wintering bat populations and it was feared that humans might carry this mysterious illness from one cave to another. Hikers, photographers and spelunkers are among those who frequent abandoned mines, caves and other locations that likely shelter hibernating bats.

Caves near Albany, N.Y. with up to 11,000 bats proved to have more than 50% of the area’s wintering population. - were found dead, and many showed symptoms of the mysterious disease. The white fungus was found on bats hibernating in New York and southwest Vermont, and because bats migrate hundreds of miles to their summer range, the impact to other areas hibernating bats could be significant.

The affected species include the Indiana bat, listed as endangered in New Jersey and nationwide. Wildlife experts report that little brown bats are sustaining the largest number of deaths, along with northern long-eared, eastern pipistrelle and other bat species using the same caves.

Now, the "white nose syndrome" has spread to NJ, according the New Jersey Division of Fish and Wildlife. The fungus was found on many of the dead bats found inside and outside three former mines in Rockaway Township and Denville, where the bulk of New Jersey's bat populations are found. This includes our largest bat hibernation spot (hibernaculum) at the Hibernia Mine.

The bats being impacted the most, at this point, appear to be the common little brown bat. Though the endangered Indiana bat has not been found with the disease, it is likely that species also will be impacted.

Bats that have developed the white fungus around their nose and wing membranes will take flight out of their caves when they should be hibernating during winter months.

Hibernating bats are particularly vulnerable to disease or disturbance because they congregate in large numbers in caves and mines, forming tight clusters of 300 per square foot in some locations. Tens of thousands of bats hibernate in New Jersey in a small number of abandoned mines.