Sea-Tac biologist tweaks airport ecosystems to manage bird threats
As the resident wildlife biologist at Seattle-Tacoma International Airport, Steve Osmek is in charge of making sure animals play nice with the planes. Preventing bird strikes is a big part of his job, and ecosystem conservation helps him do that.
Seattle Times staff reporter
Steve Osmek is standing next to a tangle of shrubs and wildflowers, talking about conservation. But every 45 seconds or so, a jet rumbles overhead — drowning out all his words.
He’s used to the planes by now. As the resident wildlife biologist at Seattle-Tacoma International Airport, Osmek is in charge of making sure animals play nice with the planes. “If it moves, if it has legs, I’m responsible,” he says.
Sometimes, it’s simply a matter of keeping animals out, like the 12-foot fence that prevents coyotes and deer from wandering onto the runways. But it’s more complicated for the airport’s greatest wildlife hazard: birds.
Bird strikes cost the U.S. aviation industry $700 million annually, according to the Federal Aviation Administration, and more than 200 people have died as a result of bird-plane collisions in the past quarter-century worldwide. When a flight taking off from New York’s LaGuardia Airport lost engine power after hitting a flock of geese but landed safely in the river in 2009, it was called “Miracle on the Hudson” for good reason. Sea-Tac had an emergency landing of its own in 2002, when a Boeing 737 struck 26 birds.
There’s no barrier to put up against birds. Instead, Osmek is talking about conservation biology in a grassy field next to Sea-Tac.
Airports are ecosystems despite all the concrete. They’re home not only to planes and trucks but also pigeons, voles, grasshoppers, blackberry shrubs, and even salmon, in the case of Sea-Tac. Managing bird strikes is about creating environments that discourage the hazardous birds, especially ones that flock, like European starlings, or large birds of prey, like red-tailed hawks.
That means Osmek is actually responsible for things that don’t move and don’t have legs, either; he also has to think about plants.
Inside the airfield, pavement alternates with patches of grass, kept short to discourage rodents or insects that attract birds looking for food. The topsoil is low in nutrition, to prevent grass from growing tall in the first place. And the grass seeds themselves were chosen because they contain a fungus whose taste drives away waterfowl.
Around the airfield is a buffer zone of 2,646 acres. Plants with berries, nuts and seeds that attract birds are kept to a minimum. Instead, Sea-Tac plants shrubs with dense cover that discourages nesting. Goats were brought in to mow down the especially pervasive blackberries in 2008, but they were a little too good at their job; they ate all the desirable plants, too. Now the landscaping is done by humans.
Sea-Tac in the forefront
Sea-Tac was the first airport to hire a wildlife biologist, in the 1970s. Only a handful of airports across the country have wildlife biologists on staff, though most contract such positions out to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service.
“Sea-Tac has one of the longest histories of wildlife management,” said Ed Herricks, a professor emeritus in civil engineering at the University of Illinois. Herricks leads a pilot project using radar to detect birds at a few airports including Sea-Tac, chosen in part because of its detailed wildlife-management records.
Nationally, airports are ramping up their efforts against bird strikes. The number of damaging bird strikes has decreased in recent decades, while wildlife populations and the number of aircraft have increased.
Osmek began his career in marine mammal conservation at the National Oceanic and Atmospheric Administration in Seattle. He then moved to New York, where he worked on bird strikes at several airports, and came back 13 years ago to work for the Port of Seattle, which oversees Sea-Tac in addition to the harbor.
“We got into this because we love animals,” he said. “Here you’re trying to mitigate bird-strike hazards, and so much can be done with conservation.”
Even the airport’s artificial structures plug into a larger natural ecosystem. Take the stormwater-detention ponds. To keep away waterfowl like Canada geese, which are large and like to flock, the ponds are covered in nets and lined with black plastic to prevent plants that attract birds. This strategy has driven waterfowl away from the ponds.
As unnatural as all this plastic is, these ponds have a conservation role. Because of all the asphalt around the airport, rainwater runoff can overwhelm salmon creeks nearby, so the water is drained into these pools instead. In the summer, the ponds can augment low water flow.
Airports, like any habitat, are subject to the whims of nature. Two years ago, the number of bird strikes at Sea-Tac was especially high; the 121 reported incidents were nearly twice the usual number. The culprit? Voles, small mammals resembling mice, which had proliferated during an especially wet spring and attracted birds of prey.
Osmek and his team trapped and relocated more than 100 birds in 2011; this year, which has been drier, they’ve relocated 40 so far. The birds are tagged and taken to northern Washington on Bellair’s airport shuttles, and they choose to stay in those skies.
The most interesting part of the traps for birds of prey may be their bait: pigeons culled from the flock terrorizing the airport’s parking garages. A pair of pigeons both spectacularly lucky and unlucky are cooped in the trap’s bottom portion. They’re fed and domesticated — sometimes they even lay eggs, according to Osmek. But they have to regularly endure hawks swooping down and almost eating them.
Invasive bird species, like European starlings, are euthanized rather than relocated. Osmek estimates they take out a couple thousand starlings every year, and their bodies are given to the Burke Museum, which no longer has to buy birds for students to dissect.
Since live trapping and other initiatives began in 2000, Osmek says, they’ve seen a big decrease in the starling population. At the same time, the airport’s surrounding area is now home to more songbirds, which do not flock.
Sea-Tac is also the first airport with an avian radar system, started as a pilot program to validate using radar to detect birds. Since it was installed in 2007, the system has been refined. At first, airport duty managers would respond any time a single bird showed up on the radar, but by the time they got to the site in their trucks, the bird would be gone. Now they know to look only for flocks, which are dispersed with fireworks-type “screamers and bangers.”
Ultimately, there’s no way for an airport to be perfectly friendly to the environment. It’s humans who are encroaching on the domain of wildlife. Instead of fighting nature with more concrete and asphalt, which invariably leads to unintended consequences, humans can play by nature’s rules, too. And that’s why even airports need wildlife biologists.
Sarah Zhang: 206-464-2195 or firstname.lastname@example.org. On twitter @sarahzhang