As Fatal Epidemic Looms, Bat Walk Showcases Local Species
Two times this summer, rabid bats have been found in Seattle’s Madison Park neighborhood. Health officials say it was an unusual coincidence, not a sign of an outbreak. But it doesn’t help the reputation of a creature that’s facing an epidemic. White-nose syndrome has been spreading westward from New York.
At dusk on a recent evening, some 20 people gathered at Seattle’s Greenlake. A static popping sound filled the evening air as they scanned the horizon for bats. The pops came from special detectors that bring the bat's high-pitched navigation calls into human hearing range.
“There we go," says John Bassett, a retired biology professor. "That is his echolocation. That’s a scream that he’s making."
Now retired from a 40-year career dedicated to the study of bats, Bassett was the host of the shore-side presentation.
“They’re an addiction. You keep coming back to them. They do so many unique things and present so many interesting biological problems,” he says.
Bats are the world's only flying mammal, says Bassett, and echolocation allows them to feed in the dark, for example. (Flying squirrels actually only glide, says Bassett.)
Vampire bats have evolved with a mouth that can morph into a straw-like shape, he says. They also have a special blood thinner in their saliva.
“Once they get blood flowing, this anti-coagulant keeps it flowing. And once they get it going, the goal is to get it going to just enough where you can fill yourself up, but not be inundated. Not have the faucet on too much, if you will," he said.
They also have extra-long thumbs to help propel them into flight after feeding, since they often consume as much as their body weight. But, Bassett tells the crowd, only three of the more than a thousand bat species subsist on blood; most eat insects or fruit or pollen.
“The question is: what do bats do for people?" he asks, then repeats back answers offered up by his audience: "They eat bugs, that’s number one. They also do pollination.”
Bats, Bassett explains, pollinate everything from agave to cashews. And their guano has been a big moneymaker. Scooped up from caves in the south for use as a fertilizer, the U.S. government estimates bat waste saves agricultural industries billions of dollars that would otherwise be spent on pesticides.
Bassett’s presentation is an offering of the local nonprofit group, Bats Northwest. The group aims to improve the image of what they say is one of the world’s most misunderstood creatures. Board member Michelle Noe says her fascination comes from knowing that researchers are still learning useful things about them.
“We’re analyzing their flights for military vehicles. The vampire bat, we analyzed its saliva and got drugs for heart patientsm" she said. "So there’s a lot to learn and a lot these guys can help us with.”
And though it hasn't yet affected bats in the western U.S., a tragic disease called the White-nose syndrome has plagued the bat population in the east. The fungus infects the bats while they hibernate.
“The bats go back to the caves. They get all comfy and go to sleep. And all of the sudden, they wake up itching like crazy," Bassett says. "And they literally won’t go back to sleep. And they use of their fat reserves, which are designed to get them through five or six months. They burn it up very quick, and they die of starvation.”
White-nose syndrome has killed millions of bats since it spread from New York, where it was first discovered six years ago. Researchers believe it came from Europe, through trade or tourism. Its spores have now been found as far west as Minnesota.
Bassett says if the fungus reaches Washington state, it could devastate all but five or six species of bats found here. He’s reminded of how Dutch elm disease killed off the cathedral-like trees he remembers from his youth.
“The elms disappeared when I was a kid in Indiana in the '50s. I moved out here in the '70s, and we still had American elms that have now disappeared. So it got here. It just took it longer,” he says.
Bassett says tree-dwelling and migrating bats don’t seem to be affected by the fungus. But he predicts the rest will be a lot less visible if white-nose syndrome arrives here.
Washington state Department of Fish and Wildlife has received about $70,000 in federal grants to address the problem over the last three years. As hibernation season begins, they’re asking people to be on the lookout for bat deaths or erratic behavior, and to report anything they find.
And a reminder from the experts: people should never handle bats with bare hands as they can carry rabies, which often proves fatal.
Bats Northwest hosts free bat walks at Greenlake every summer. They're over for this season, but will start up again next June.