In 2022, an ornithologist high in the Sierra Nevada de Santa Marta mountains of northern Colombia spotted the shimmering emerald green and cobalt blue feathers of the Santa Marta sabrewing. A large hummingbird, it had only been documented twice since 1879. As the bird sat on a branch the ornithologist, Yurgen Vega, captured images.

Once lost to science, it now was found.

The bird was on the American Bird Conservancy’s 10 most wanted list, which sits atop a longer register of “lost birds,” which are formally defined as not having been documented by photographic, audio or genetic evidence in at least a decade.

A major goal of the list is to persuade bird watchers and others to look for these birds as they go out into the field, and to bring back evidence the birds have not gone extinct.

People have searched for lost birds for decades. But the process was formalized in 2020 by the conservancy, in partnership with two other groups, Re:wild and BirdLife International, as the Search for Lost Birds project.

Researchers from the groups published a paper in June with a definitive list of birds that need finding. They scoured tens of millions of photos, videos and audio recordings in birding databases such as iNaturalist and xeno-canto. The study concluded that there are 144 species of bird lost to the scientific world but that may still exist.