Back road bat mobile in The Last Green Valley
During the summer months my wife, Julie, and I drive the Bat Mobile along the dark roads of Windham County. Our patrol route is a 20-mile transect of small country roads between Windham and Putnam. While I would like you to think we are driving one of the most famous crime-fighting machines, we’re actually driving one of our completely normal cars and conducting an important monthly citizen science project — recording bats.
Julie drives the bat mobile and I ride shotgun with a laptop (in my lap) loaded with sophisticated mapping and recording software. She drives slowly, between 17 to 20 miles per hour, while a large highly sensitive microphone attached to the vehicle roof records the echolocation calls of feeding bats. I refer to us as bat man and bat woman. Julie prefers to call it “date night with Ranger Bill.”
Echolocation is a type of sonar bats use to navigate in the dark while searching out and feeding on flying insects. The bats create high frequency pulses of sound and listen for the returning echo to create a mental picture of their surroundings that allows them to locate and catch flying insects.
While driving our prescribed route the microphone and recording system pick up these sound waves and create a date and location sound file on the laptop. We keep the volume up on equipment so we can hear the sound of the bats. While Julie drives, I watch as waves of bat calls flash across the laptop screen.
Biologists then use the recordings to classify the different bat species by their individual vocalizations. This way they can establish which species are present in the recordings. With samples from several evenings during the summer, they can estimate the numbers and species of bats in each area. In essence we are creating a census that counts bat species numbers by their own distinctive echolocation calls. This data is another important component to understanding what is happening to our bat population across the state.
Our prescribed route between Windham and Putnam is one of nine across the state recording bat echolocation calls twice a month. We only go out on warm nights of 70 degrees or more and no rain. Our drive starts 20 minutes after sunset and usually takes us about an hour to complete.
The survey is an important step in understanding our bat populations, which have been in sharp decline since the onset of white-nose syndrome (WNS). Local bat populations have been decimated — especially the species called little brown bat.
I have been reading up on WNS to learn more about its deadly impacts. I subscribe to both Connecticut Wildlife and Massachusetts Wildlife magazines and found the No. 3. 2019 issue of Massachusetts Wildlife to have an excellent article, “Bath Myths Debunked,” by Jennifer Longsdorf, Mass Wildlife Bat Conservation Coordinator. Here is her description of White-nose syndrome.
“In North America, an estimated 6.7 million bats have died since 2006 from an outbreak of White-nose syndrome (WNS), a rapidly spreading disease caused by a fungus that invades and ingests the bare skin of hibernating bats while they are inactive (Massachusetts Wildlife, No. 3, 2011). WNS increases bat metabolism, causing bats to wake up more frequently during the winter and use up their precious fat reserves. Bats ultimately starve to death, but the fungus also compromises their immune systems and creates holes in their wings leading to dehydration.”
WNS infects cave-roosting bats, where the air is moist and the fungus can spread. It was first discovered in Connecticut in 2008. The deadly fungus is called Pseudogymonascus destructans. If you see a bat flying about in the cold winter months, more than likely it is infected with WNS.
The little brown bat, one of our region’s species of cave-roosting bats, has been hit the hardest. Here is Longsdorf’s description of what has happened to this species in Massachusetts.
“At the largest Massachusetts bat hibernation site in an abandoned mine in Chester, there were about 10,000 little brown bats (Myotis lucifugus) in early winter 2007–2008. By the end of winter 2008–2009, nearly every bat had been killed by WNS … only 14 individual bats remained. The little brown bat used to be the most abundant and widespread bat species in Massachusetts. Since the onset of WNS in Massachusetts, the state’s population of little brown bats has dwindled to less than 1% of what it once was. As a result of the devastating mortality that has resulted from WNS in Massachusetts, all four of our bat species that spend the winters in caves or mines have been listed as endangered on the Massachusetts Endangered Species Act list. Of the nine bat species that occur in the Commonwealth, five are now state endangered including the Indiana bat which was last recorded in 1939.”
Learning more about the deadly impact of WNS has given me an increased appreciation for the biologists who are working hard to gather data on our bat populations and to undertake conservation efforts across our region.
There are a few on-line sources of information you may be interested in reading to learn more about WNS and efforts to record bat echolocation.
The Massachusetts Wildlife magazine article referenced in this column can be found at:
For a “deep-dive” on WNS and its impacts nationally check out this website:
Julie and I hope to continue our volunteer citizen science effort for CT DEEP during the summer of 2020. I am sure the folks there would welcome others to help in their important efforts to monitor bats. Brian Hess, Wildlife Biologist with CT DEEP has suggested if you’re interested in helping to monitor known bat roosts or to report bat sightings to go to the following CT DEEP website link:
In my years at The Last Green Valley I have come to appreciate the fascinating creatures who share our fields, waters and forests. Bats are important to us as they are the primary predator of night-flying insects, including mosquitos known to spread the serious infectious disease Eastern Equine Encephalitis (EEE). Bats have a very high metabolism and can eat up to 125 percent of their body weight in insects in a single night! That’s a lot of mosquitos.
The more we know, the better our management decisions and conservation practices. Bats are important and deserve our attention. We live in a beautiful place called The Last Green Valley. I hope you’ll join me and so many others as we enjoy it, care for it, and pass it on.
Along with the sources linked above in this column, information for this column was gleaned from Connecticut Wildlife Magazine, November/December 2015, Listening to Bats: a Glimpse into the Night, by CT DEEP Wildlife Biologist Kate Moran.
Bill Reid is the Chief Ranger of The Last Green Valley National Heritage Corridor and has lived in the region for more than 35 years. He can be reached at firstname.lastname@example.org
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