As Weather Warms, Bats Emerge From Hibernation And Begin To Appear On Maine's Landscape

By MDIFW Wildlife Biologist Sarah Boyden It’s been a cold spring with late season snow storms keeping parts of the state covered in snow.  As the temperature slowly warms, bats appear on the landscape returning to their summer habitat.  Five species of bats are year-round residents in Maine.  They survive the winter cold by entering underground habitat called hibernacula. In Maine, there are only a handful of known hibernacula consisting of caves and mines where bats hibernate through the winter. Even though we only know of a few, there are likely many more hibernacula across the state that remain a mystery.  Researchers from the Maine Department of Inland Fisheries and Wildlife are conducting surveys across the state to learn more about bat hibernacula in our region. Over the past decade, several of our most common bat species have declined over 90% following the spread of a fungal disease called, White Nose Syndrome.  It’s normal for hibernating bats to wake up periodically during the winter but bats infected with White Nose Syndrome wake much more frequently and use up their winter fat reserves, sometimes causing them to leave the cave in the dead of winter searching for food. Spring is a difficult time of year for bats as they emerge from hibernation.  Many species will return to the same area and even the same roost year after year.  Roosts include trees with cracks, crevices or flaking bark, or rocky slopes that provide shelter.  One way to help bats in the spring is to leave standing dead trees, called snags, on your property.  Snag trees typically have flaking bark, or other features that provide daytime cover for bats.  Also, consider adding a bat house to your property.  Bat houses create roosting habitat and can be purchased at your local farm and garden store, or are easily constructed using tutorials from Bat Conservation International (www.batcon.org). Bats eat hundreds of insects each night, including black flies and mosquitos.  With black fly season right around the corner, it’s always a welcome site to watch bats swooping across the night sky eating insects in the backyard.  Visit www.maine.gov to learn more about Maine’s bats as they return to the landscape this spring.