ALBANY — To raise awareness about the critical role of bats in the environment during internationally recognized Bat Week, New York State Department of Environmental Conservation (DEC) Interim Commissioner Sean Mahar encouraged outdoor enthusiasts to refrain from visiting caves and mines during the fall and winter months.
Bats spend the winter hibernating in underground cavities where relatively constant, warm temperatures protect them from harsh winter temperatures above ground. Bats’ health is particularly vulnerable to human visitation at these “hibernacula” in the winter, and especially harmful since the arrival of white-nose syndrome, a fungus that has killed more than 90% of bats at hibernation sites in the state.
“Bats play a critical role in our environment and in pollination of many commercially and locally important fruit species,” Mahar said. “In New York state, native bats help control insect populations and temper the impacts of outbreaks of spongy moths and other common forest and agricultural pests. DEC urges outdoor adventurers to protect New York’s bats by avoiding caves and mines altogether. Even the quietest cave visits will disturb bats settling down for the winter.”
There are nine species of bats in New York, six of which are “cave bats,” meaning they hibernate in caves and mines throughout the winter, while the three tree bat species migrate to warmer areas.
All of these bats need to build up fat stores in the fall to ensure they have enough energy to carry them through their long hibernation or migration; they do this by consuming up to their bodyweight in insects each night.
During this time, known as the fall swarm, bats are also congregating in large numbers to mate. For cave bats, this means they are using their hibernation sites to find potential mates before hunkering down inside for the winter, making these sites even more valuable to them.
All bat species help control pest populations by feeding on insects. Their voracious appetites can help limit the amount of pesticides needed for crops and gardens, reduce mosquito numbers, and may help limit the spread of invasive insects in New York. In recent years, scientists have found evidence of recovery of the once-common little brown bat throughout New York state. While this provides a hopeful outlook for this species, similar evidence of stabilization has not been seen for other severely affected bat species.
Two species of bats, Indiana bat and northern long-eared bat, are currently protected under federal and state endangered species law. Indiana bat was listed as endangered before white-nose syndrome began affecting bat populations. The northern long-eared bat population is 1% of its previous size, making this species the most severely affected by white-nose syndrome.
DEC reminds the public to follow all posted notices restricting access to caves and mines. If outdoor enthusiasts discover bats hibernating in a cave, DEC urges visitors to leave quickly and quietly to minimize disturbance. Anyone entering a listed bat hibernation site from Oct. 1 through April 30, the typical hibernation period for bats, may be subject to fines.
Other ways people can help bats in New York include:
- Planting a pollinator garden to increase prey availability for bats, who feed on insects;
- Putting up a bat box on their property to offer bats a summer roost safe from predators and human activity (see options for bat box designs and DIY instructions); and,
- Contacting a bat certified Nuisance Wildlife Control Operator (NWCO) when looking to remove bats safely from their homes (find a list of NWCOs)