Correction: A previous version of this article referred to a mobile bat detector as the Anabat CF2. The correct name for that model of bat detector is actually the Anabat SD2, a spokesperson for the manufacturer of the Anabat SD2 informed the Empire.
America’s bats are in a bad way. Since 2006, a deadly fungal disease known as white-nose syndrome (WNS) has ravaged bat populations across America, killing an estimated 6 million with as much as 99 percent fatality.
WNS still hasn’t found its way to Alaska, but if and when it does, scientists at the Alaska Department of Fish and Game want to be prepared. To do so, they say they’ll need to help of citizen scientists.
Bat monitoring through ADF&G’s Threatened, Endangered and Diversity Program will start up in a few weeks, wildlife biologist Tory Rhoads explained to the Empire on Friday. The monitoring program takes place in two parts: a stationary, or passive monitoring program, conducted by ADF&G staff, and an active, mobile component, which both biologists and volunteers will help with.
On a wet, snowy Friday morning on Douglas’ Fish Creek, Rhoads demonstrated how both work. Rhoads was in the area, a hotbed for bat activity, to change a battery and check on one of ADF&G’s bat monitoring stations.
The device Rhoads was servicing, which looks like a high-tech mailbox, picks up and records ultrasonic bat calls inaudible to the human ear. Ultrasound is all around us, Rhoads said.
“(Bats) are emitting decibels close to that of running a chainsaw, we just can’t hear it,” she said.
Bats use ultrasound to map their surroundings. Recording and analyzing this will help Rhoads understand where bats live around Juneau and what their habits are.
The data might help Rhoads recognize white-nose syndrome if and when it spreads to Southeast Alaska. Bats hibernate and are nocturnal, so Rhoads didn’t expect to see a bat Friday morning at Fish Creek. If she did, it would have been a big red flag for WNS.
“If we get reports of sick bats in the winter, we get really scared,” Rhoads said.
Rhoads explained it this way: bats are on “low power” to survive during hibernation. Just like bears, they fatten up in preparation the winter. But WNS causes bats to grow a snow-hued fungus on their noses and wings, agitating bats and causing them to wake up.
“White-nose is thought to be itchy to them,” Rhoads said. “So it’s kind of eating away at their wing tissue, it’s tickling their nose, it’s all over their face. It causes them to wake up.”
Once awake, a bat boots up fully, so to speak, and its metabolism starts working like normal, demanding the bats to eat. But finding food is much harder in the winter. Consequently, a bat with white-nose syndrome will use up its fat stores and eventually starve or dehydrate itself to death.
“White-nose doesn’t kill bats per say,” Rhoads said. “They die from dehydration and starvation.”
Five of ADF&G’s monitoring stations like these are scattered about Juneau. There’s one near Kowee Creek, the Mendenhall Glacier, Fish Creek, Auke Lake and near the Airport Dike Trail.
The Fish Creek station is the most productive of the five. On a peak night of bat activity, Rhoads has logged as many as 500 bat calls. Other stations peak out with much lower numbers.
Up at the Fish Creek parking lot, Rhoads demonstrated the second half of her bat monitoring program. It’s facilitated by something called the Anabat SD2. Just like Rhoad’s monitoring station, it’s designed to pick up and record ultrasonic sound.
The Anabat SD2 connects to a mic with a powerful magnet on the bottom. It’s meant to be placed on the roof of a car.
It can also replay bat calls in real time. She demonstrated.
“Rub your fingers together,” Rhoads said.
As expected, it didn’t produce an audible noise. But once Rhoads turned on the Anabat SD2, a sharp, loud clicking could be heard, corresponding with the back-and-forth rubbing of this reporter’s fingers.
Rhoads hopes citizen scientists will familiarize themselves with the technology. Part of her and project lead Karen Blejwas’ research necessitates doing driving surveys as well as stationary monitoring. They just don’t have enough personnel, even if she could pull the whole ADF&G wildlife division, Rhoads said, to conduct the driving surveys.
The driving surveys produce data the stationary monitoring can’t, she said. Because a bat could be simply flying back and forth around their stationary monitors, they can’t say with confidence how many bats the stationary monitors are picking up. The driving surveys are conducted at 20 mph, which means two calls heard on a driving survey would most likely come from separate bats.
Driving surveys take about an hour and half in Juneau, depending on which of the two paths taken. They’re also conducted in Sitka, Wrangell, Haines, Cordova and Petersburg.
Citizen scientists in Juneau can sign up by visiting the Mendenhall Glacier Visitor Center, where Juneau’s Anabat SD2 resides, or by contacting ADF&G’s wildlife division at 465-4265. All the instructions and equipment are provided in a small kit that comes with the Anabat SD2.
Those volunteering to turn their cars into batmobiles are asked to keep the equipment for a week and complete at least one driving survey. After that, volunteers are free to use the equipment to search for bats in other areas of town, Rhoads said, or complete multiple surveys.
• Contact reporter Kevin Gullufsen at 523-2228 or kgullufsen@juneauempire.com. Follow him on Twitter at @KevinGullufsen.
Alaska Department of Fish and Game Wildlife Biologist Tory Rhoads holds a specimen of the so-called “little brown bat,” Alaska’s most populous bat species. (Kevin Gullufsen | Juneau Empire)
