Missing for Decades: Researchers Identify Over 500 Species As “Lost”

A new research has discovered 562 extinct species.

An multinational research identifies more than 500 'lost' species—those that have not been spotted by anybody in more than 50 years—and gives the first global evaluation of all terrestrial vertebrate species that have not been declared extinct.

Researchers looked at data from the 32,802 species on the International Union for Conservation of Nature's Red List of Threatened Species (IUCN Red List) and found 562 lost species.

The IUCN Red List defines extinct as "when there is no reasonable doubt that the last member of a species has died," which is difficult to verify.

The Red List ranks 75 of the 562 lost species as 'possibly extinct,' according to Arne Mooers, a biodiversity professor at Simon Fraser University and research co-author. According to the researchers, the presence of multiple species with uncertain conservation status might become more troublesome if the extinction crisis intensifies and more species perish.

Since 1500, 311 terrestrial vertebrate species have been proclaimed extinct, suggesting that 80 percent more species have been declared lost than extinct.

Reptiles were first, with 257 species believed gone, followed by 137 amphibian species, 130 mammalian species, and 38 bird species. The majority of the missing animals were last spotted in megadiverse nations like Indonesia (69 species), Mexico (33 species), and Brazil (33 species) (29 species).

Miles’ robber frog (Craugastor milesi), is endemic to Honduras and thought to be extinct but was rediscovered in 2008

This concentration is crucial, according to academics, despite the fact that it is not unusual. “The fact most of these lost species are found in megadiverse tropical countries is worrying, given such countries are expected to experience the highest numbers of extinctions in the coming decades,” says Tom Martin of Paignton Zoo in the United Kingdom.

“While theoretical estimates of ongoing ‘extinction rates’ are fine and good, looking hard for actual species seems better,” says Mooers, the study's lead author.

“We hope this simple study will help make these lost species a focus in future searches," says Gareth Bennett, an SFU undergraduate student who handled much of the data combing.

Future survey efforts should focus on the identified 'hotspots,' where the presence of many specific species is still in doubt, according to the scientists. More money would be required to enable hotspot-targeted fieldwork in order to either rediscover lost species or dispel reasonable doubt that a specific lost species still exists.

Reference: “‘Lost’ taxa and their conservation implications” by T. E. Martin, G. C. Bennett, A. Fairbairn and A. O. Mooers, 16 May 2022, Animal Conservation.

DOI: 10.1111/acv.12788