The Vilacabamba brush-finch has a bright yellow breast and an orange crown. It was last seen in Peru in 1968.
The Siau scops-owl was last seen 155 years ago in Indonesia when it was first described by scientists. Since then, there have been unconfirmed reports of a bird that matches the description of the speckled brown owl with yellow eyes. But much of its forest habitat has been destroyed.
These are just two of the 10 bird species that researchers are trying to find after being lost to science for years. The Search for Lost Birds is calling on scientists, conservationists, and birdwatchers to help locate these lost birds. The project is a collaboration between Re:wild, American Bird Conservancy (ABC), and BirdLife International, with data from the Cornell Lab of Ornithology and its eBird platform.
It’s part of Re:wild’s Search for Lost Species program, which has rediscovered eight of its top 25 most wanted lost species since its launch in 2017.
Out of 11,003 bird species recognized by BirdLife International and the International Union for Conservation of Nature (IUCN), 1,450 species are classified as threatened on the IUCN Red List of Threatened Species. That’s more than one in eight, Roger Safford, senior program manager for preventing extinctions at BirdLife International, tells Treehugger.
That includes birds that are categorized as vulnerable, endangered, and critically endangered, and a few that are extinct in the wild, meaning they survive only in captivity.
“Around 48% of all bird species worldwide are known or suspected to be declining, compared to 39% that are stable and 6% increasing and 7% with unknown trends,” Safford says. “There have also been studies estimating the numbers of individual birds lost in certain parts of the world in recent decades, perhaps most remarkably the finding that the U.S. and Canada have lost more than one in four birds—a total of three billion—since 1970.”
With so many dwindling species, the birds on the list were those not treated as extinct by the IUCN, but they haven’t been definitely observed with some sort of proof, such as a photo, in more than 10 years.
Researchers also considered conservation urgency, as well as the potential to support a project or expedition to search for them, John C. Mittermeier, director of threatened species outreach at American Bird Conservancy, tells Treehugger.
Although scientists find all the birds on the list fascinating, a few already stand out.
“Jerdon’s courser is a remarkable case—a relatively large bird living in central India, a densely populated region with many brilliant field observers, but it is nocturnal and elusive, so very hard to find,” Safford says. “It was lost for many decades after its discovery, found again in 1986, but not seen since 2009. Habitat has been destroyed in the meantime, but we should not give up hope.”
Mittermeier is also intrigued by the Siau scops-owl, which is known only from a single specimen collected from a small island off Sulawesi, Indonesia, in 1866.
“There’s still some forest on the island where it lives and a few people have gone to look for it, but no one has seen it since its initial discovery,” he says. “Is it still there and really hard to find? Or did it go extinct this past century without scientists realizing? One specimen from more than 150 years ago is about as mysterious as a bird can get.”
Another riveting bird is the Santa Marta sabrewing which was relatively common in South America until the 1940s.
“Sixty years later a single sabrewing was caught and released in 2010 only for the species to disappear again,” Mittermeier says. “No one has seen it since! We don’t know why it declined, where that single bird came from or if there are more Santa Marta sabrewings somewhere out there.”
Lost Versus Extinct
The 10 lost birds span five continents and many groups of species, from hummingbirds to raptors.
Researchers explain the difference between “lost” and “extinct.”
“Extinct means there is no reasonable doubt that the last individual of a species has died,” Safford says. “Lost implies that there is reasonable doubt, or even a strong likelihood, that it is still out there. The evidence for this might be habitat still existing, inadequate searching, difficulty of detection, or unproven but plausible reports.”
Scientists say it’s often difficult to know why the populations of these species have declined because they know so little about them.
“In some cases, though, we can predict why the birds have most likely declined,” says Mittermeier. “Habitat destruction has likely led to the decline of Jerdon’s courser, for example, while invasive species almost certainly contributed to the disappearance of the South Island Kokako.”
Researchers are optimistic that some of the species will be found by scientists or birders who are on the lookout for the elusive birds.
“Some might be called low-hanging fruits (strong chance) and others long-shots … But no ‘fruits’ are so ‘low-hanging’ that we expect it to be easy, or someone would have found them already!” Safford says. “The general point is that these species may still exist, and sometimes no one has looked for them. Any expedition that gets us more answers or clues, even if it doesn’t find its intended species, is a good thing.”
