The unexpected discovery two years ago of Northern Saw-whet Owls on Isle au Haut and other remote islands in the Gulf of Maine by biologists at the Biodiversity Research Institute in Gorham underscored the significance of migratory routes and stopovers for birds and bats, especially in the siting of wind turbines. Until then, it was not known that Saw-whets fly over open water. This year BRI intensified its investigation of the owls’ migration. And Susan Sharon recently tagged along to a banding station in Falmouth.
It’s just after 6:00 p.m. at the Riverpoint Conservation Area in Falmouth and biologists Patrick Keenan and Kate Williams from BRI are setting up three tall, finely-threaded nets between trees near the Presumpscot River in the dark. Bright red lights from an adjacent Hannaford parking lot glow in the distance. And traffic hums on a busy highway nearby. This is one of a half-dozen Saw-whet banding sites BRI operates in Maine.
“You can probably tell, Kate, I chose here because we’re kind of up on this high ridge and I thought if birds are coming up they will amost definitely get caught,” Keenan says.
Keenan and Williams are trying to catch and band Northern Saw-whet owls, (a researcher holds one in the photo above) a small, lightweight Disney-cartoon-looking creature, about six-to-eight inches long with a round white face, a dark beak and yellow eyes. Saw-whets nest in tree cavities across forests in North America. And although they are not uncommon, they are nocturnal and difficult to see in the wild.
“We’re really at the southern end of their breeding range,” Williams says. “Mostly it’s the northern forest in Canada. And then some birds will come from way far north and actually winter here and some birds will continue past us further south.”
To capture and band Saw-whets the biologists use a pre-recorded call of the owl on a playback machine that they strategically place near the nets. It’s louder than the call the birds usually make. But Williams says females, in particular, seem attracted to it. For people, though, it’s another story.
“And one of the reasons we perch ourselves far away is because this sound–I actually wake up in the morning with this sound, like, playing in my head,” Keenan says.
Just down a short trail and around a corner, the BRI team has set up a banding station in a small barn. Wearing headlamps and drinking thermoses of coffee to stay warm, the pair will check the nets every half an hour until midnight to see if any owls get caught in the nets. Once caught, they use small pliers to attach specially-numbered bands on their tiny legs, record the bird’s sex, it’s weight, wing measurement and overall body condition.
“Unfortunately, Saw-whet’s are too small to put, say, a satellite transmitter on them or anything, so you can’t actually track individuals yet. The technology is not quite there,” Williams says. “So in the meantime, we’re left with banding birds and then trying to recatch them in other locations, and looking at those recaptures and trying to sort of guess where the birds went in between.”
So far this year, Williams says she has captured 160 Saw-whets at just two stations along the Maine coast. Her biggest take ever was 26 Saw-whet owls at one site. Keenan’s was 32. Both say they’re on track to catch more than 300 owls this year, the number that was netted this summer.
Doing this work takes patience, good weather, stamina and lots of luck. Keenan says it’s even made him superstitious. “So my lucky green socks are 0 for 2 this year, so they’re retired for the season,” he jokes. “Tonight they’re mixed–these are solid, I’ve been wearing these all week. We’ve had a really good week.”
On this night, Keenan and Williams have invited several of their colleagues and their friends to join them. As the temperatures drop and the first net check comes up empty, the group tries not to lose faith. At about 8:30, a second foray is made out to the woods.
“All right I have great news everyone,” Keenan says. “Our third net has come through and it’s just as we planned. The bird is flying this direction toward the speaker. So we caught a Saw-whet. We did it. We actually did it.”
Keenan puts the tiny owl in a small bag and carries the bird back to the banding station where her data are carefully recorded. Williams says as many as 80 percent of the owls she’s caught have been female. One theory is that males may not migrate as much as females and may try to spend the winter in the cavities of old trees.
But this project may shed light on that question, and others that could arise in the siting of windpower projects on land as well as offshore.
“And if you know enough about migratory routes you can put turbines in out of, say, a migratory fly away, but to do that you have to know where those fly aways are,” Williams says. “And for a lot of birds, especially their off-shore migration routes, we just don’t know where they are and where they go yet.”
After being banded with number 34991, it’s time to release the Saw-whet just outside the barn. But the little owl is a reluctant flier. “All right, buddy. Let’s do it,” Keenan coaxes. “There we go. Oh. I just blew a little bit on his underparts.”
Tina Ouellette of Saco, BRI’s accounting manager, and Julia Ackerman of Whitefield, were there to observe. “This was incredible,” Ouellette says. “To see them in pictures and to be right there holding one. It’s a good feeling.”
“It was a very moving and a very spiritual experience for me,” Ackerman says. “I think I’ll come back.”