Bat Week continues… In Part 1, we talked a little about bats, and their importance to the environment. We then followed the intrepid Heinz Refuge Bat Team into the field to search for these important critters by recording their high-pitched echolocation calls.
We left the team with lots of memory cards filled by chatty batties…
A lot of people are spooked by bats. Perhaps because when they are photographed in flight, they always have their mouths wide open and pointy little teeth on display. It looks intimidating, until you consider how small our local bats are. Those teeth are for eating tiny insects, not humans; and the reason their mouths are always open is because they’re always talking. They need to echolocate continuously while they’re flying, both to hunt and for navigation.
Armed with recordings of all that chatter, Refuge Biologist Brendalee and I returned to the office. That’s where the magic happened.
Sophisticated computer software turned bat call files into sonograms, graphic representations of the sound waves. Each bat species’ echolocation call is unique, and by analyzing and comparing our recorded calls to a library of reference calls, the software was able to tell us who made the call.
From those identifications, we learned that six species of bats can be found at Heinz Refuge from June to October. Big Brown, Eastern Red and Silver-Haired bats were found throughout the Refuge, Hoary and Evening Bats dropped by most locations, and Tricolored Bats were infrequent visitors to a few of our sites.
Big brown bats (Eptesicus fuscus) are known as cave bats because they hibernate in caves and mines as well as buildings during the winter. They are common in the area, and frequently encountered because they will roost in buildings, including attics during the summer. Robb had one get into his house and after letting the little guy out the front door, he called me to complain.
Yes, bats do get into houses sometimes. Attics are nice cozy places to roost. Robb did the right thing. If a bat is flying in your house, open doors and windows to the outside, turn off the lights and wait quietly; the bat will find his way out. If it’s roosting in your attic, call a professional who knows how – and when – to deal with it humanely.
I saw this Eastern Red Bat (Lasiuris borealis) roosting in a lilac bush at Mt. Cuba Center a few years ago. Eastern reds like to pretend they’re dead leaves. Hanging from one foot, with their fur-covered tail wrapped around them, they’re pretty good at it! They’re solitary bats, roosting and hibernating in trees, behind tree bark and in leaf litter.
This old cell phone image is the only photo I have taken of a bat. All other bat photos here were taken by USFWS and NPS photographers. My journey with bats has just begun; perhaps bat photography is in my future.
Hoary bats (Lasiurus cinereus, above) are long-distance migrants. They are thought to occur in all 50 states, and are the only bat found in Hawaii. The name comes from the silvery frosting on their fur.
Silver-haired bats (Lasionycteris noctivagans) and Evening Bats (Nycticeius humeralis) were also found this summer at Heinz Refuge.
Finding Tricolored Bats (Perimyotis subflavus) at the Refuge is of particular interest, as this species is on the verge of being listed as endangered in the state of Pennsylvania. This is where the story of bats turns dark; bats are in trouble!
These vital critters are being decimated by White-nose Syndrome, a fungus that affects hibernating bats. It grows in damp dark spaces like caves and attacks skin, including the thin membranes of the wings. It sometimes appears as a white fuzz on bats’ faces. The lesions rouse them from hibernation, causing them to burn vital energy that they need to survive the winter.
White-nose Syndrome has killed millions of bats since its discovery in 2006. Little Brown, Northern Long-eared and our own Tri-colored Bats have been especially hard hit. There’s no known way to stop this scourge, at least at the moment. But the U.S. Fish and Wildlife Service is partnering with other organizations and scientists to learn everything they can about the disease, in hopes of containing it and one day overcoming it.
Which is why FWS is conducting bat surveys at Refuges across the Eastern U.S. Brendalee offered me the chance to help with Heinz Refuge’s survey, and I jumped in with both feet. Now I am batty about bats!
While I am absorbing every bit of information about bats that I can, I have only seen a handful in my life. Mt. Cuba and Tyler Arboretum. A few along Lake Michigan, including the little fellow that got in the house while I was there this summer, who we clumsily rescued and released. (Note to Club Mich folks – opening a window is probably better for the bat than nets!)
On the last day of our survey in early October, I walked along Darby Creek in the Refuge in search of bats. Fifteen minutes after sunset, I found myself in the midst of a cloud of feeding bats. I shot a little video on my cell phone; you can view it here. It looks like a bunch of trees, but keep watching the sky as bats zip in and out.
It was too dark to see the bats as anything other than silhouettes against the sky, so I don’t know what species they were, but it didn’t matter. I stood in awe of these silent, agile creatures as they darted over the creek, catching bugs. Think bats are creepy? Think again. We are much better off for the presence of bats in our lives.
I don’t want to live in a world where there are no bats.