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.
The study concluded that there are 144 species of bird lost to the scientific world but that may still exist.
Organizations:
conservancy, BirdLife International