The takeaway: Birds not listed as endangered but also not seen in years are termed “lost”—and there are global efforts to document these lost birds. These efforts have produced some incredible results.

In the world of zoology there are three primary classifications: least concern, endangered, and critically endangered. These classification categories rank species based on their risk of global extinction. American robins and humpback whales are ranked “least concern” while the black rhino and yellow-crested cockatoo are critically endangered.

But there’s another classification that biologists use, and you can play a role in getting bird species on and off of it–lost.

What Are Lost Birds?

“Lost” birds are a birdwatching community and ecological reference to bird species that have not been seen for 10 or more years but are not officially declared extinct. 

Lost birds are sometimes called “lost species” or “possibly extinct.” Birds are officially classified as “lost” by a group called Search for Lost Birds, which is a partnership between Re:wild, BirdLife International, and the American Bird Conservancy.

How Many Lost Birds Are There?

According to the Search for Lost Birds, the lost bird list currently has 126 species, which is 1.2% of all bird species. These have not been documented–either by photo, video, or audio–in at least 10 years, but are not yet classified as extinct. Official extinction classifications are declared by the International Union for the Conservation of Nature. Assessments are performed by scientists, conservationists, and taxonomy experts through the group’s Species Survival Commission.

What Is the Difference Between a “Lost” Bird and an “Extinct” Bird?

To be classified as extinct, these officials must come to the conclusion that there is no reasonable doubt that the last individual has died. That means that:

  • There have been exhaustive surveys in known and expected habitats

  • Those surveys were conducted at the appropriate times

  • Surveys covered their historic range

  • And all this work produced no evidence at all

This classification is distinct from lost birds, for which there is still a chance it exists and scientists are holding out hope of rediscovery.

The Challenge of Finding Lost Birds

Lost birds fall into a nebulous region scientifically. These are not confirmed extinct but also not recently seen–and often for good reason.

As told by the American Bird Conservancy, most lost birds have historic habitats in equatorial regions, particularly in equatorial South America and Africa, and also the equatorial islands and mainland areas of the western Pacific such as New Guinea.

Finding lost species in these areas is particularly challenging:

  • Many countries, such as the Democratic Republic of Congo, have challenging political environments that discourage visits, even scientific expeditions, and are regions where there is frequent armed conflict, food shortages, and general strife.

  • Many of these regions, even when politically relatively stable, simply lack reasonable access–think vast roadless jungles with little in the way of even dry ground, much less an airport with commercial air service and a guide waiting to whisk you to the forest.

  • Many of the lost birds once endemic to these regions would be notoriously difficult to spot even if they were more common. Many are canopy species who live up to 200 feet off the ground and in dense foliage that blocks visibility. Others are extremely shy and quiet, with soft, high-pitched sounds that are difficult to detect. And they may rarely fly long distances in the air. Bird spotting in these regions may require camera traps, drones, autonomous recording units, and tree climbing using ropes and other specialized equipment.

Lost Bird Species in North America and Europe

While not nearly as common as in equatorial regions, there are officially labeled lost bird species in North America and Europe.

  • In North America, there are currently 13 lost species, including six native to Hawaii and three in the continental U.S.: Eskimo Curlew, Bachman’s Warbler, and Ivory-billed Woodpecker.

  • In the United Kingdom, lost bird species include Kentish Plover (not seen since 1928), the Black Tern (not seen since the 1850s), and the Red-backed Shrike (not seen since 1988).

Discovering Lost Birds: Recent Success Stories

While the thought of a lost bird is concerning, it’s not all doom and gloom. Some recently found “lost” birds provide wonder and inspiration:

  • Black-Naped Pheasant-Pigeon, photographed in 2022 on Fergusson Island in Papua New Guinea, previously documented in 1882

  • White-tailed Tityra, known from a single specimen collected in 1829 near the Madeira River in Brazil, then sighted in 2006 and photographed in 2022

  • New Britain Goshawk, photographed in 2024, last confirmed in 1969

  • Dusky Tetraka, native to Madagascar and seen in January 2023 after going missing since 1999

  • Mussau Triller, native to Papua New Guinea and last documented in 1979 but spotted in June 2024

Why Finding Lost Birds Is Important

The global search for lost birds is important because the findings can fill in important gaps in our knowledge about these species and their habitats.

Updated information on lost species is vital for conservation efforts, as communities cannot protect what they cannot find. The presence of lost birds highlights global gaps in citizen science–which is something all bird watchers can contribute to.

In 2024, the last year for which complete data are available, eight lost birds were rediscovered while five were declared extinct and 11 were added to the lost bird list. (Notably, some lost bird species may not be distinct species at all, but instead misidentified known species, individuals with unusual plumage or malformations, or accidental hybrids between two known species.)

Since 2022, 30 lost bird species have been found, representing about 23% of the lost birds list–an impressive number considering the rarity of these species and the general difficulty in navigating their habitat. The most common way a lost bird is rediscovered is not from a major expedition–it’s from an independent birder working with local conservation groups. While roughly half of all lost bird species are feared extinct, many are simply data deficient–they are likely out there, it just takes time, money, and muddy boots to find them.

How You Can Help Find Lost Birds

No, you don’t have to be a member of a National Geographic Society expedition to search for lost species. Much of the effort, officials say, will come from engagement with local birding communities, and that can happen in concert with amateur but enthusiastic bird watchers like yourself. 

Are you searching for lost birds either at home or on birding trips? Even if you find nothing, you should report your efforts to the Search for Lost Birds. (Unsuccessful searches help provide clues about where to conduct subsequent searches.) Need help getting your own search off the ground? Several organizations help coordinate lost bird search efforts, and some even offer grant money for expeditions.

Can you spot a lost bird species at your smart bird feeder? It’s possible but unlikely, since there are only a handful of lost birds thought to be present in North America and the United States. Most lost birds are shy, nocturnal, and even if they do exist, their numbers may only total a few dozen, meaning the odds of seeing one at your garden feeder are astronomically unlikely.

Still, crazier things have happened. The White-tailed Tityra just happened to be spotted by a birder who was in the right place at the right time, and not conducting lost species research. The Black-Naped Pheasant-Pigeon had been spotted by villagers in Papua New Guinea for years but they didn’t think it was important. And in 1997, a birdwatcher happened upon a Forest Owlet in India, a bird that has been missing for more than a century. Most people who think they’ve seen a lost bird at their feeder are actually seeing a vagrant, hybrid, or color morph–highlighting why a smart bird feeder must have a high-quality camera and motion detection system.

Ready to launch your own birding expedition from the comfort of your living room sofa?  Follow this link to learn more about FeatherSnap smart bird feeders and start your own journey of discovery.