In 1989, when the Exxon Valdez oil spill coated hundreds of birds in an impenetrable slime in Alaska’s Prince William Sound, the ornithology branch at Seattle's Burke Museum received an influx of dead specimens—1,500 of them, to be exact. The hope was that even though they had lost their lives in the horrible accident, these birds could live on by contributing to science. The Burke Museum is well known for its wide collection of preserved bird specimens, but on that occasion, it wasn't practical to preserve so many oil-soaked bodies.
Instead, the museum's ornithologists decided to rescue what they could—the wings. “It was a way to make a quick and dirty specimen out of a bird that wasn't otherwise very useful,” says John Klicka. Klicka wasn't at the museum during the time of the spill but is now the ornithology department's curator and, as the position requires, has become skilled at preserving wings.
Of the specimens, ultimately the museum salvaged 1,100 wing sets, and those formed the foundation of the museum’s now 26,000-strong expansive collection. Today, it occupies an unusual niche: it's the site of the largest spread wing collection in the world, one with a captive audience of researchers and artists who visit the museum to study its specimens.
The museum initially started collecting wings because its emeritus bird curator, Sievert Rowher, used them to study patterns of feather molt. When the spill occurred, the collection grew—and then continued to grow as the museum became increasingly famous for its wings.
The museum doesn't only collect wings. “We have over 100,000 study skins, and one of the largest tissue collections in the world,” Klicka says.
Where do they come from?
One wing is collected from each specimen the museum receives, Klicka explains. The other is left on to allow ornithologists to study a bird that's at least partly intact. In some cases, wings come from specimens that have been damaged, during a flight collision for example. “Sometimes that stuff is in pretty bad condition, but we could still potentially take a wing,” says Klicka. “The idea when you collect any specimen is to maximize its usefulness.”
How are wings removed?
As one might expect, with some cracking and cutting: There's no room for squeamishness here. First, the wing is loosed from the body with a scalpel, in a process called "de-articulation." Then Klicka uses scissors to sever the wing at its tertial layer—the line of feathers that bridges the body and the wing. Once it’s severed, it can be easily snipped free. “Then what you'll do is you'll peel the wing back a little and take as much meat out as you can.” This ensures that the wings don’t decay, or attract any pests that may infest the precious specimens.
This method allows the wings to be preserved as spreads—if a wing were preserved still attached to a bird, it would stiffen and be impossible to view in full. The Burke Museum is particularly famous because it has such a large collection of spread wings.
How are they preserved and stored?
The museum doesn't use chemicals on its specimens, relying only on air-drying and bug-free storage to keep them uncontaminated. “We air dry them, catalog them, and put them away,” Klicka says. Placed inside special envelopes, the wings are then slotted into storage cabinets, like a vast catalog of files. Each one bears a tag that links it back to the parent bird, which often lies elsewhere in the collection.
How do wings differ from one another?
Color, size, and shape are what make wings visually unique, and those differences also have important functional roles to play. “Every bird wing is a reflection of that bird's life history and habits,” says Cooper French, Klicka’s colleague and a biology graduate student at the University of Washington, who’s used the Burke’s collection in his studies.
For instance, a wing’s aspect ratio—its measurement tip-to-tip, combined with its area—conveys information about the bird’s flight style. Eagles have a large aspect ratio, which makes them good at gliding. A pheasant’s shorter, stubbier wings preclude gliding, but allow the bird to lift off the ground very rapidly. The shape of the wing matters, too. Deep indentations in the flight feathers called trailing-edge notches will give birds such as turkeys an aerodynamic advantage by enhancing their ability to lift and maneuver even at slow speeds, which helps them dodge predators.
Feather colors and patterns turn wings into the stunning canvasses that help camouflage birds and give them their vibrant mating displays, French says. “The Golden Pheasant is a classic example of a female with dark brown mottling perfect for hiding, while the males go all out with extravagant reds, golds, and blues.” The colors and patterns also help birds recognise their kin and group together with them.
What can we learn from wings?
Burke's collection has a keen following of physiologists who study feathers and flight. Scientists have used the collection to investigate the patterns of flight, feather molt and replacement, and how precise wing shapes give rise to particular flight displays. Painters, sketch artists, and photographers enjoy access to the wing collection too, and arrive from far and wide to view it. “Artists love the idea of having open wings,” says Klicka.
Why keep saving wings?
Such collections build a kind of insurance, Klicka says. They’ll provide a record of the current avian world, and build a showcase of diversity. “One of the fascinating things about what we do is that we don't know exactly what people in 100 years are going to want to study.” Specially preserving and tagging wings enriches the collection and helps current-day ornithologists provide more groundwork for future researchers. “You're documenting the biodiversity that occurs outside the museum,” Klicka says. “Each specimen is kind of like a library book that has a different story to tell.”