By: Shreya Dasgupta, Mongabay

In September this year, while tramping the forests of Guadalcanal, an ornithologist named Christopher Filardi, from the American Museum of Natural History spotted a male mustachioed kingfisher (Actenoides bougainvillei excelsus), a “ghost bird” that he had been seeking for 20 years in the jungles of the Solomon Islands. A beautiful creature – or was – bright blue with a striking golden head, a white breast and blue plumes stretching back from the beak that give it its name.

But although it was the only one he had ever seen, rather than trapping the bird, taking its measurements and releasing it, Filardis killed it. He preserved it as a specimen. An article that he wrote in Audubon Magazine describing the episode has kicked off an enormous global furor, with more than 800 people writing in to Audubon, a staid magazine published in the United States, weighing in pro and con about  his having killed the last known bird of its kind.

Not so fast

It isn’t that simple. If it’s the last of its kind, or even the last of a small number of its kind, it is probably headed for extinction anyway and preservation of what it looks like and its DNA may be the best course.

For instance, in an interesting demonstration a decade ago, researchers concerned by how avian pox was wiping out several bird species on the Hawaiian Island wanted to find out if the disease was a threat to a unique bird species of another group of islands. The team investigated which avian pox viruses were affecting birds in the Galapagos Islands off the coast of Ecuador, and when and how these viruses may have been introduced there. They believed that determining this would help them protect the birds.

They found some of their answers in museum specimens. Between 2004 and 2008, the team combed through more than 10,000 specimens of stuffed birds — including thousands of mockingbirds and finches — at the California Academy of Sciences and the Zoologische Staatssammlung in Munich (ZSM), Germany. Explorers had collected them during expeditions to the Galapagos Islands between 1891 and 1908.

The team found that only specimens collected after 1898 had wart-like growths consistent with avian pox, suggesting that avian pox could have appeared in the Galapagos Islands in the early 20th century.  The spread of avian pox echoed the movement of humans to the Galapagos, the team found, indicating that humans and their pet birds were possibly the source of the disease. The team even sequenced some of the pox viruses isolated from the century-old specimens and found that the strains infecting birds in the Galapagos and Hawaiian Islands were different.

The museum bird specimens,  killed and collected from the Galapagos Islands more than 100 years ago, helped the team map the historical timeline of a debilitating avian disease.

“Without museum collections, work like this would never be possible,” Jack Dumbacher, Curator of Ornithology at CAS, told the Guardian in 2011. “Because museum specimens include detailed collection date and location data, they can be used to study not only a particular species, but also historical events and environmental conditions.”

All those stuffed things

Indeed, museum collections are fascinating. Many of us probably still gawk at stuffed collections of extant and extinct birds, beetles, vibrantly-colored butterflies and other animals that fill up glass cases and exhibition halls.

Many of these collections were borne out of expeditions to remote parts of the world, treks that involved trapping, killing, preserving and cataloging animals that explorers encountered. Many of these collections have been useful in shaping what we know of the natural world.

For instance, Charles Darwin’s collection of birds from his travel aboard The Beagle — particularly those collected on the Galapagos Islands — is believed to have inspired his theory of evolution. We also know of now-extinct animals like the dodo from museum specimens alone.