Smithsonian tracks bird strikes for military, airline industry

Feather identification experts determine what types of birds are colliding with jet engines, which can make flying safer for everyone--including the birds.

Dr. Carla Dove using a comparison microscope to study feather structure in the Birds Division at the Museum of Natural History. Photo: Chip Clark

When I visited the Feather Identification Lab at the Smithsonian’s Museum of Natural History, Dr. Carla Dove pulled out a stack of manila folders thicker than a phone book, filled with reports of bird strikes from around the world. Each included a form and a Ziploc bag. Some bags contained whole feathers, others contained specimens that looked liked specks of dirt, but were in fact bird remains.

“These are all from last week,” Dove said.

The lab--the world’s only full-time department that studies bird strikes-- was created in the 1960s, by Dove’s predecessor, Roxie Laybourne. Working for Laybourne, Dove was so enthusiastic about the field that she went to graduate school and studied environmental science and public policy, with a focus on the microstructure of feathers. It didn’t take her long to realize that the work performed in this little lab is a big help to the military, the aviation industry and of course, the birds.

“They started to realize if we know the birds on the airfield,” Dove said, “they can change the habitat.” Not only can bird strikes threaten the safety of a flight, but they can cause millions of dollars in damage to the aircraft. So the Federal Aviation Administration and the military fund the Smithsonian lab in order to learn more about the strikes and how to prevent them. The two groups have separate databases where Dove’s team logs each incident. Commercial airlines report strikes on a voluntary basis; for the military, it’s mandatory.

What we do know about strikes is that most happen at takeoff and landing, typically at the engine, but sometimes at the windshield or even the plane’s wheel well. The culprit is usually a bird, but Dove’s reports have also included bats, deer and—on overseas U.S. military bases—animals including goats and pigs. Strikes also happen at all altitudes; the record for the highest strike goes to a Griffon Vulture flying over Africa.

But there’s a lot that we don’t know when a strike occurs: the species, whether it was more than one species, and whether it was a resident or visitor bird. In fact pilots don’t necessarily know that a strike even happens; it’s often those cleaning the jet’s engines who find the debris, called snarge. And that’s what is placed in a Ziploc and mailed to Dove and her three colleagues.

“If we have a feather, we can take it out to the collection [the 150-year-old Smithsonian bird collection], identify it and then email the field person with the ID,” Dove says. “If it’s just blood or tissue, we send it to the DNA lab and can usually get the DNA sequence within a week. If we can’t do that—sometimes it’s in really bad shape after being in the engine—we’ll look at the microscopic characters in the fluffy down. Even if it’s just a piece of down, we can tell, for example, whether it’s a duck or a bird.”

Carla Dove, Nancy Rotzel and Marcy Heacker use the museum’s bird collection to identify birds that are involved in bird strikes. Photo: James DiLoreto

Once the bird is identified, the information is entered into a database and sent to the airfield where the strike occurred. This information helps biologists build airfield habitats that are unfriendly to the types of birds causing problems. “If you let the grass grow, that will deter some birds,” Dove said. “But that may not work at another airfield. You might have long grasses that attract mice and a bird that eats mice. You have to know how to manage it.”

Dove and her team worked on the remains of the geese from the 2009 US Airways landing in the Hudson River. In fact, they’re still working on it, trying to determine from DNA samples exactly how many geese hit the plane. The remains of the geese were hand-delivered to the Smithsonian within two days of the accident, and the team was able to sex the samples and determine there were at least one or two birds, eight pounds each, from a migratory population. But there also could have been as many as three or four. “We’re working with the [National Transportation Safety Board] to refine it,” Dove said. “It’s like a detective story.”

With this incident, the public became more aware of the danger that birds can pose to aviation safety. But when wildlife biologists and the U.S. Department of Agriculture killed nearly 400 geese this summer because they lived in Brooklyn’s Prospect Park—too close to New York’s La Guardia and Kennedy airports—some residents were appalled.

I asked Dove, who goes birding in her spare time, what she thought about the Prospect Park geese. “I love birds, but when it comes to the airports, they have got to control these geese,” she said. “They’re doing the right thing.”

Airplane engines—which go through “bird tests”—are designed to handle strikes with certain weights of birds, typically four pounds, according to Dove. “The 777 is certified for eight pounds, but only one [bird],” she said, not four. “How much would it cost to design an engine for eight-pound birds? How heavy would it be? There are all questions that are being asked.”

In the meantime, the number of eight-pound geese have grown. Strike reports have increased dramatically, but Dove isn't sure if that’s largely because more airfields are reporting, or because there are more strikes. She arrived at the lab in 1989, and there were 300 cases a year. Today there are more than 5,000.

Out of 10,000 species of birds, only about 350 to 400 are involved in strikes, but it can still be tricky to identify them. I looked at one Ziploc, for example, that held a tissue with a brown, coffee-like stain. Turns out it was all that remained from a Brazilian freetail bat from a Southwest Airlines flight from Sacramento, a Boeing 737 that departed at dusk.

In her office, Dove has a comparison microscope, where she can put a known sample next to an unknown sample, examining the fluffy barbs and the suite of characters—the length, node shape and location—at a high magnification. “If you have triangular-shaped nodes, only at the end, we know it’s a waterfowl,” she tells me, as I peer into the scope. “It took me about 10 years to get comfortable with the detailed microscopy. There’s no one to follow in my footsteps. We’re trying to get a grant to get an apprentice.”

So what does Dove do when she boards a commercial jet? Naturally: “We’re always looking out the window for birds,” she said. “But we feel safe because of the people on the field who are working to make it safer.”

This post was originally published on Smartplanet.com

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