Federal transportation officials confirmed in February that US Airways Flight 1549, which splashed into the Hudson River on January 15, had ingested Canada Geese into its engines.
Now scientists at the Smithsonian Institution, after examining feather remains from the bird strike, have determined that the geese involved were from a migratory, rather than resident, population. The team's findings are being published in the journal Frontiers in Ecology and the Environment today, June 8.
Researchers in the Feather Identification Laboratory at the Smithsonian's National Museum of Natural History applied DNA barcoding, a method that compares a segment of DNA to a database of known genetic material, to the tissue remains of birds extracted from the plane's engines. Whole feathers were also compared with research specimens at the Smithsonian. The DNA matched that of Canada Geese, and the individuals were estimated at about eight pounds each.
Read the profile of the Smithsonian's Feather Lab from our April 2009 issue (subscriber access only).
The team took their research to a molecular level at the Smithsonian Museum Conservation Institute labs in Suitland, Maryland, where they examined stable-hydrogen isotopes from the feathers to confirm whether the geese were from resident or migratory populations. Stable-hydrogen isotope values in feathers can serve as geographic markers since they reflect the types of vegetation in the bird's diet at the time it grew new feathers after molting.
Using a mass spectrometer, which measures the masses and relative concentrations of atoms and molecules at high precision, the scientists compared the bird-strike feather samples with samples both from migratory Canada Geese and from resident geese close to LaGuardia Airport, departure point of Fight 1549. Analysis revealed that the isotope values were most similar to migratory Canada Geese from the Labrador region of Canada and significantly different from resident feathers collected in New York City.
The finding doesn't necessarily mean the birds nested in Labrador, but that their isotopic signatures match those of geese from the area, says Carla Dove, a coauthor of today's paper and the program director at the Feather Lab.
"It's important not only to know what species of birds are involved in collisions but also to understand the role that migration plays in the larger picture," Dove says. "The more information we are able to gather in cases like this, the more we will be able to reduce the risks of bird strikes in the future."
The geese apparently chose to winter in the New York City area. She says their behavior at the time of the accident -- flying at about 3,000 feet -- "is more conducive to moving in search of food and moving around in response to weather." A cold front had passed through, and the weather at the time of the strike was marked by snow and frigid temperatures.
"I hope the paper will result in more interest," Dove adds, "in bird migration, movements, and research on how, when, and why birds get up and move." -- M.M.
In the wake of the crash of Flight 1549, columnist Pete Dunne marvels at how, even at airports, birds go about their business while we go about ours (subscriber access only).
When we talk about birdstrikes, says editor Chuck Hagner, we need to drop the us-vs.-them mentality.
Top photo: USDA Wildlife Services personnel remove feathers from an engine of the US Airways Airbus A320 that crashed into the Hudson River in January. Bottom photo: The jet is lifted out of the Hudson River after the crash. Both photos courtesy of the National Transportation Safety Board.