New York’s 325 big brown bat records are led by Tompkins County around Ithaca, with Ulster and Onondaga next and Long Island’s Suffolk and Kings counties close behind. It’s surely undercounted even so, because it roosts in places people don’t always think to check.
Long Island’s buildings do the job of a cave
Long Island has little of the rock crevice and cave habitat this bat can use elsewhere, but it doesn’t need that here. Big brown bats roost readily in attics, barns, church steeples, and bridge joints, and Long Island’s mix of older houses, farm outbuildings, and shoreline structures gives them exactly that kind of shelter. In the Adirondacks and Catskills, the same species falls back on tree bark, rock crevices, and cliff cracks instead.
New York’s own white-nose syndrome story
Big brown bats are recorded here through the same winters that gutted New York’s cave-hibernating bats. White-nose syndrome, the fungal disease that has killed millions of North American bats since it was first documented in a cave near Albany in the winter of 2006 to 2007, hits little brown bats and Indiana bats hardest. Big brown bats tolerate colder, drier winter sites and have fared better, which is part of why this species still turns up across the state while some of its cave-mates have all but vanished from New York’s hibernation sites.
Two summer peaks, not one
Records rise in May, dip briefly, then climb again through July and August. That double peak likely reflects maternity colonies settling in early summer, followed by young bats taking flight and feeding heavily on beetles and other insects before fall.
Status in New York
NatureServe ranks the big brown bat S5, secure, and it’s native to New York. Its ability to use buildings alongside natural roosts has made it one of the state’s more resilient bats through a period that has been brutal for several of its relatives.
Full species profile
