I visited James and museum specialist Chris Milensky to learn about Martha and the exhibit she anchors: Once There Were Billions: Vanished Birds of North America. I wanted to know how the Smithsonian preserved the world's last living passenger pigeon. What does it take to keep a 100-year-old carcass in pristine shape? How much longer will Martha last? And what can she still teach us?

Immediately after Martha's body was discovered in the Cincinnati Zoo, scientists rushed to pack her into a 300-pound block of ice, then onto a train bound for Washington. Smithsonian officials received her three days later in "fine condition," according to an account written by R.W. Shufeldt, the man who performed her dissection. (He did note, however, that some of her tail feathers were missing.) The significance of the moment wasn't lost on Shufeldt, who recalled the loss in an article published by the American Ornithologists' Union: "With the final throb of that heart, still another bird became extinct for all time," he wrote, "the last representative of countless millions and unnumbered generations of its kind practically exterminated through man's agency." (A historical aside: Shufeldt may have written tenderly about Martha, but he’s also infamous for publishing horrific racist screeds about white supremacy under titles like The Negro: A Menace to American Civilization.)

While it's not clear exactly how Martha's body was prepared for exhibit back in 1914, Milensky told me that it must have been a difficult job. "Pigeons are one of the hardest birds to prepare," he says. "They have extremely thin skin—and the skin is attached to the body very tightly." The bird must be skinned and de-fatted, which prevents specimen breakdown later. It’s an extremely delicate procedure; if it isn't done carefully, the feathers along the bird’s rump and back can fall out all at once. "The fact that they were able to throw it in a block of ice, transport it all the way to D.C., thaw it, skin it out, mount it, and have it look nice is a testament to the skill of the people involved," Milensky says.

After Martha was skinned, her internal organs were stored in jars of ethyl alcohol. (The Smithsonian still has those, too. They're kept off-site in the museum's fluid collection.) Then, according to Shufeldt's account, a taxidermist named Nelson R. Wood prepared the skin on an artificial body most likely made from wire, shredded bits of wood, and tightly wound bundles of string. "You wrap the skin around it, sew it shut, and run wires or whatever else you have to do to make it solid and tight," Milensky says. Once a mounted specimen is sewn shut, it's set for good. From that moment in 1914 until the day her skin inevitably breaks down—whenever that may be—Martha will remain perched on that stick, head cocked at a harsh angle to the side.

R.W. Shufeldt

The passenger pigeon was, for a long time, the most common bird in North America. It comprised as many as two out of every five birds found on the continent. James estimates that 6 billion of them may have been alive at the species' peak. They flew in flocks by the hundreds of millions, if not billions—such a tremendous number, in fact, that 19th-century witnesses reported they would blot out the sun for hours at a time. In 1813, John James Audubon described a migrating flock in western Kentucky as an "eclipse" that obscured the midday light. "The dung fell in spots, not unlike melting flakes of snow," he wrote. If every rock pigeon alive today—all 260 million of them—flew in a single flock, it would be one-eighth the size of a group sighted in the early 1800s by ornithologist Alexander Wilson. The species laid waste to forests where they roosted, as Jonathan Rosen explains in the New Yorker, snapping limbs from trees and coating the ground in foot-tall piles of toxic droppings. They even affected our language: Terms like "stool pigeon" and "trap shooting" originate from methods used to hunt and kill these birds.