The night shift is beginning.
The swallows have gone to roost on the shores of Green Lake, having finished their daily hunt for flying insects. The bats will take over at dusk.
First we hear a clicking noise, picked up by a palm-held bat detector/transmitter. Then we see a bat fluttering against the pink and blue sunset sky in a break between the trees. Bats Northwest volunteers John Bassett and Michelle Noe, leaders of the organization’s bi-monthly “Bat Walks,” identify it as big brown bat. It has a furry body about 4.5 inches long and a wingspan of about a foot, fully extended. From where we stand it doesn’t look nearly that big, and can be easily mistaken for a bird.
It’s joined by another, then another, until there are six bats circling among the treetops. Ten minutes later, Noe and Bassett identify a slightly smaller and slower silver-haired bat. Bats often hunt in shifts, Bassett says, with one species following another.
We hear the clicking as the bats fly in our direction, and don’t hear it when they turn away. “They’re screaming at 110 decibels, but on a frequency we can’t hear,” Noe explains. They’re sending out the high frequency sounds and then using the echoes to determine what’s in front of them, an amazing sort of biological sonar called echolocation. The detector translates the sounds into clicks we can hear, differing by species of bat.
Bat walk is a misnomer, as we stay in one spot on a grassy knoll near Green Lake. Some of the 15 species of bats found in Washington state are arranged in display cases on the picnic table, along with stuffed animal bats for kids to play with. In the 45 minutes between the start of the bat walk and the appearance of the first bats, Bassett expounds upon the creatures that have fascinated him for 40 years as a research scientist, using colorful illustrations and props to punctuate his talk. Noe or another volunteer does the children’s presentation.
You’ll learn dozens of fascinating things if you join a bat walk, beginning with the fact that bats are mammals, the only ones capable of powered flight. They’re not rodents or “flying mice;” they aren’t blind; they like to stay warm; and they hibernate in winter in tree snags, caves or attics. They pollinate lots of the things we like to eat and drink, from cashews to some kinds of bananas to agave cactus, and in the Northwest they eat millions of mosquitoes and other flying insects. And no, we don’t have any “vampire bats” in Washington, although Bassett does describe how the South American varieties suck blood and keep it flowing freely.
Bat walks are recommended for children 6 years and older, but younger ones are welcome. If your child doesn’t have the attention span to stand around for 45 minutes, arrive just before dusk to see the flying bats. Events are held rain or shine, but you’re unlikely to see any bats if it’s raining or very windy. You’ll see the most on warm, sunny summer evenings.
Once you’ve learned about these fascinating creatures, take a walk at dusk near any source of water and see if you can see these unobtrusive nocturnal hunters.
