That is, they haven’t been seen by anyone in more than 50 years. But are they really gone for good?
Researchers reviewed information on 32,802 species from the International Union for Conservation of Nature Red List of Threatened Species (IUCN Red List) and identified 562 lost species. Their findings appear in the journal Animal Conservation.
The IUCN Red List defines extinct as ‘when there is no reasonable doubt the last individual of a species has died,’ which can be challenging to verify. According to Simon Fraser University biodiversity professor and study co-author Arne Mooers, the Red List categorizes 75 of these 562 lost species as ‘possibly extinct.’ The researchers note the existence of many species with an uncertain conservation status may become increasingly problematic as the extinction crisis worsens and more species go missing.
A total of 311 terrestrial vertebrate species have been declared extinct since 1500, meaning 80 per cent more species are considered lost than have been declared extinct.
Reptiles led the way with 257 species considered lost, followed by 137 species of amphibians, 130 species of mammals and 38 species of birds. Most of these lost animals were last seen in megadiverse countries such as Indonesia (69 species), Mexico (33 species) and Brazil (29 species).
While not surprising, this concentration is important, according to researchers. “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 study lead author Tom Martin from the UK’s Paignton Zoo.
Mooers, who anchored the study, says: “While theoretical estimates of ongoing ‘extinction rates’ are fine and good, looking hard for actual species seems better.”
Simon Fraser University, “Lost or extinct? Study finds the existence of more than 500 animal species remains uncertain” at Eurekalert (May 19, 2022)
The paper has “limited shared access.”
Apart from loss of habitat due to human encroachment, it would be interesting to know whether there is much study of patterns that govern extinctions — that is, natural extinctions. Paleontologist David Raup (1933–2015) wrote quite a good book on the topic, Extinction: Bad Genes or Bad Luck in 1991 but it’s not clear how much has been done since then.
A species of moth, not seen since 1912, was found inside a passenger’s luggage at the Detroit Metropolitan Airport.
U.S. Customs and Border Protection found larvae and pupae from the moth last September inside a bag arriving from the Philippines.
Sheri Walsh, “Moth last seen 110 years ago found at Detroit airport” at UPI (May 18, 2022)
The moth larvae and pupae were destroyed, as a potential agricultural pest.
You may also wish to read: At Mind Matters News: Did small brains doom the mammoth and the giant armadillo? Before we decide, let us hear a word in defense of small brains. The topic is not as simple as many think.
and
Extinction (or maybe not): New Scientist offers five “Lazarus species”