The Winter World of Bats

A few years ago, when I was working for the state, I had the opportunity to visit a place that not many humans have a chance to visit.  Deep within an old abandoned mine in upstate NY.

One cold winter day, after a few mile snowshoe, deep into the woods, we arrived at what should have been the entrance to the mine. Unbeknownst to us a collapse had sealed off the entrance, which sent the group searching for a new way underground.  After sliding on my stomach through a hole, and dropping down a rock slide, I made it into the underworld.  Why on earth did I venture deep into the unknown?  Bats of course.

I was assisting in a bat survey to assess the population and the extent of the White Nose Syndrome. Being deep underground is like nothing else.  When you turn off your light, there is nothing.  There is no wind, no sound, until the bats start chirping.  In this underworld cave, there were amazing ice formations, sculpted by drops of water falling from the roof.  That same roof, held the slumbering bats that we were there to count.

Bats are of the order Chiroptera, meaning flying hand.  Due to a membrane, they have  webbed wings.  Bats are the only mammals that can truly fly, the flying squirrel only glides.  All bats within the Adirondacks eat insect, you know those biting, annoying, buzzing things that people spend hours swatting and complaining about.

While there is a small chance that you will see a bat during the day, they are generally nocturnal, and feed at night when they use echolocation to navigate and hunt.  Most bats within the Adirondacks breed in fall to winter with the female storing the sperm for conception in the spring.  There are nine bats that are noted within the Adirondacks and upstate NY: Big Brown Bat, Eastern Pipistrelle, Silver-haired Bat, Hoary Bat, Eastern Red Bat, Indiana Bat, Northern Myotis, Little Brown Bat, Eastern Small-footed Bat.

Not all bats hibernate in caves or old mines, some will actually migrate to warmer climates like the Silver-haired Bat, Eastern Red Bat and the Hoary Bat.  During the spring females will join together and form a maternity colony.  These can be in caves, under loose tree bark, or in buildings.  Most young are born between April and July.

In the late fall to early winter, the bats will either migrate south or seek out a cave or old mine to hibernate in.  The chosen location must have low temperatures and high humidity.  Bats can and do awaken during winter and yes fly about.  They will not feed, relying on fat stores, unless they are sick.

Interesting to note is the Indiana bat.  This species is endangered throughout its range. I was so hoping to see one deep within that cold, damp, cave.  The most common bat seen during the survey who is also the most common and hardy bat of the Adirondacks is the Big Brown Bat.

I must admit that being deep within the underworld surrounded by strange ice formations and bats, I felt like I was visiting an alien world.  It was dangerous, beautiful,  surreal.  I feel lucky to have had the chance to experience their winter world.