84 animal and plant species were considered extinct in the wild in 2022 on the International Union for Conservation of Nature (IUCN) Red List. They live only in zoos, aquariums and botanical gardens or are preserved in seed banks. The reintroduction of these species is a huge challenge, stresses zoologist Donal Smith, from the London Institute of Zoology, in Science magazine. With a current work, the researchers are attentive to this species, because the extent of the threat and the risk of extinction are only insufficiently known.
While there are still a few thousand animals or plants of some of the recorded species living only in human captivity, there are only a handful of others. According to the researchers, species are less monitored and often neglected, as the focus is often more on endangered species that are still found in the wild.
This is also demonstrated by the fact that eleven species under human care have gone extinct since 1950. Only twelve have regained the status of wild animals or plants.
According to the study, 28 to 48 existing species of birds and mammals would have been exterminated between 1993 and 2020 if measures such as habitat protection, resettlement and so-called ex situ conservation were not taken – that is, through breeding grounds or zoos.
Species that are already considered completely extinct in the wild are classified on the IUCN list in the “Extinct in the Wild” category. This category only includes species that are kept solely in culture, in captivity, or as a naturalized population far outside their former range.
some hits
“The cases we present paint a picture of more than 70 years of attempts to use ex situ conservation to prevent species from becoming extinct and facilitate their recovery”, explains Smith. Both the fragility of that status and the potential for success despite that fragility are emphasized. However, according to the IUCN, they would be overlooked as attention is generally focused only on wild populations.
The study shows that most of these populations that are extinct in the wild are small, usually less than 1,000 individuals, and have low genetic diversity due to the limited number of population founders. Furthermore, most of these plant species depend on live reproduction by a small number of owners. Even fewer are secured in seed banks.
And while reintroducing species into the wild has shown success in some species, attempts are rare, note the study authors. Smith said that without the conservation efforts of committed organizations, the sable sable, several Polynesian snails and the yellow-flowered toromiro would already be lost. The existing possibilities to bring back extinct species must be taken advantage of. But it’s a Herculean task, emphasizes co-author Axel Moehrenschlager of the IUCN. Faced with the climate crisis and the loss of biodiversity, equipment such as zoos, aquariums, botanical gardens and seed banks would continue to gain importance. (gral/apa)