Arctic snowy owls searching for a homey spot head for ... Boston's airport?
If Norman Smith has some spare time, he likes to spend it at the airport. He's not watching airplanes, though. He's watching owls.
The director of the Massachusetts Audubon Society's Blue Hills Trailside Museum in Milton, Mass., has special permission to patrol Boston's Logan International Airport. He drives his pickup near the runways, looking for snowy owls.
Mr. Smith has been peering up at the sky for as long as he can remember, straining to spot hawks and owls in flight. He's always had a special feeling for "snowies," as he calls them. The large, mostly white nocturnal birds spend most of their time in the far North.
But it's not just snowies' charm that has Smith hunkered down in his truck for hours at a time, watching owls amid the screaming jetliners. What fascinates Smith is all that's left to learn about the owls. It's the "mystique of this white creature," he says, that attracts him most.
For example, scientists know that snowy owls have four talons on each foot, instead of the usual three. They know snowies can live up to 10 years in captivity. But no one can even estimate a snowy's lifespan in the wild. Researchers know the owls live mostly above the Arctic Circle, but no one knows where, in particular, they congregate. The owls' migration habits are largely unknown, too.
Naturalists do know why snowies like Boston's airport, though. And that's where Smith comes in.
It began in 1981, when Smith got a call from the United States Fish and Wildlife Service. Could he help them trap a snowy owl living at Logan?
The owl was a hazard to planes taking off and landing. Birds, especially big birds (snowy owls can be two feet tall with wingspans of 5-1/2 feet), may be accidentally sucked into jet engines. This can severely damage the engine and even cause the airplane to crash.
A rotating three-person Bird Patrol, hired by the airport, does everything it can to reduce the bird population there. They have lots of ways to do this, including the use of "cracker shells" and propane cannons. These are big noisemakers intended to scare off the birds without hurting them. As a last resort, the Bird Patrol may shoot particularly large and persistent birds, such as sea gulls and crows. The Migratory Bird Treaty Act prevents them from shooting snowies, though. Instead, they call Smith.
Smith successfully trapped that first owl in 1981. Since then, he's been trekking to the airport at sunrise and sunset several times a week, pursuing the mystery of the snowies. He's trapped nearly 300 snowy owls to date. Logan airport, in fact, is the best place to find snowy owls around here. (You're not likely to spot the airport owls yourself without binoculars.)
The owls' natural habitat is the Arctic tundra, treeless stretches of open grass. But every year, from November to April, when many birds fly south, snowies can be found almost anywhere on the airport's 2,400 acres: on the edge of the parking garage, by runways, even perched on control towers bristling with spikes designed to keep all birds off.
Why do snowy owls like it here? The wide-open spaces and low-cut grass make it seem like home. Their favorite meal - a small rodent called a lemming - doesn't live anywhere near Boston. But the owls find plenty of other small rodents, namely meadow voles (a cousin to the lemming) and urban rats.
Not even the thunder of 1,000 planes taking off and landing daily deters the owls. While they do have extremely sensitive ears, Smith says they must get used to the noise the same way people learn to ignore traffic noise in the city. Smith fondly recalls observing one particular owl that catnapped all day in the middle of the airfield, completely unfazed by planes passing overhead. (Smith wears earplugs at the airport most of the time.)
Letting the grass grow longer at Logan might keep away a few snowies. But Smith says that nothing - not even paving the airfield completely - would make this or any airport completely bird-free.
That's why Smith is good to have on hand. He drives around the airfield in his pickup until he spots an owl. Then he'll park and set up his trap about 100 feet away. He uses a live mouse in a wire cage to lure the owl into the trap. A long string runs from the trap to his truck.
When the owl approaches the trap, Smith pulls the string, which flips a net over the owl. Just this year he's caught 22 different snowies.
He takes every owl back to the bird sanctuary in the Blue Hills, near Boston. There, he "bands" the owls, placing a numbered aluminum strip around the owl's ankle. That's so the owl can be identified later. Then he lets the owls go.
Two of this year's owls have also been fitted with small satellite transmitters. This is part of the Trailside Museum's new program to study the snowy's migration patterns. Where do the owls go, for example, when they're not at Logan?
A Teflon-coated harness attaches the transmitters to the owls like a backpack. The radios are very light - 30 grams, or about one ounce. (Male snowies weigh from three to four pounds. The usually larger females are between four and five pounds.) The harness is held on with dental floss. When the floss deteriorates in two years, the transmitter falls off. Two years is about the length of time the transmitter's batteries last.
Smith says the bird is hardly aware of the transmitter. The snowy eventually preens its feathers in such a way that only the radio's antenna is visible on its back. It transmits signals via satellite to a firm in New Jersey, which then determines the owl's exact location.
As long as the transmitter is attached and the battery is running, scientists can tell the bird's location and whether it's moving or stationary.
The Snowy Owl Telemetry Research Project is now in its third year. In two years, researchers have learned more about snowy owls' migration than they had in the past 20 years, Smith says. Some of the owls have returned briefly to Logan Airport; others have been tracked as far north as Baffin Island in Canada.
"The longer we work on this," Smith says, "the more questions we have." And the answers to some of these mysteries may lie no farther than one's backyard - or the nearest airport. All you need is a careful eye.
People sometimes ask Smith how he can tell one snowy from the other. It's the same as with people, he says: "Every single one is different," They may not be much to look at during the day, when they resemble nothing more than "big, fluffy white mounds." But at night, when they are most active, "they're spectacular."
Norman Smith has been bringing his two children on snowy owl expeditions to Boston's Logan International Airport since they were 2. But he's the first to admit that he's learned something about owls from them. In fact, not only Smith but also other owl researchers have learned a lot about owls from his oldest daughter's high-school science project.
In 1994, Danielle Smith, then a freshman, entered the Massachusetts State Science Fair. Danielle wanted to study how weather conditions affect the migration of saw-whet owls, small owls that average 7-3/4 in. tall and populate wooded areas in the Northeastern and Western United States. She proposed the nearby 476-acre Daniel Webster Wildlife Sanctuary as a research site. But her father and others discouraged her, pointing out that saw-whets had never been spotted there before.
Danielle persisted, however. "She had a hunch," her father says. But more important, she's always had a "wondering and questioning" mind.
Eventually, Mr. Smith relented, and he and Danielle set up a large mesh net in the woods that September. By the end of November, they had caught, banded, and released 10 saw-whet owls. Encouraged, they repeated the experiment the next year. Their results more than quadrupled: They caught 53 saw-whets. In 1999, they brought the project to their backyard in Whitman, Mass., about 20 miles southeast of Boston.
Danielle describes her backyard as small and almost treeless. Nevertheless, she and her father caught 36 owls that year in a trap they set up by their pool. Apparently, saw-whets pass through Greater Boston on their migratory route. They are so small, they had previously been undetected.
The project continues today. In all, Danielle and her father have trapped and banded 722 saw-whets. And the Massachusetts science fair? Danielle won second prize. But more important, she has shared her findings with other owl researchers in the Eastern United States.