Experts see an enormous challenge in reintroducing dozens of endangered species that are only found in zoos and similar institutions. "Despite heroic efforts, failure is just as common as success," said scientist Donal Smith of the London Institute of Zoology (ZSL), according to a statement.
Smith and colleagues published in the journal Science an inventory of the 84 animal and plant species that were considered extinct in the wild on the International Union for Conservation of Nature (IUCN) Red List in 2022 and are only found in zoos, aquariums, botanical gardens or seed banks .
"Without the conservation efforts of these dedicated organizations, we would have already lost species like the saber antelope, several Polynesian tree snails and the yellow-flowered toromiro," Smith said of species that no longer exist in the wild. Cases like that of the European bison even show that species that were once limited to a small population under human care can also spread again in the wild thanks to appropriate projects.
Call for more protection for species in care
While there are still a few thousand animals or plants of some of the recorded species living only in human captivity, only a handful remain for others. According to the researchers, the species are less monitored and often overlooked as the focus is often more on threatened species that are still found in the wild. This is also shown by the fact that eleven species under human care have become extinct since 1950. Only twelve would have regained status as wild animals or plants. Smith and his colleagues are calling for species protection to be significantly strengthened in this area.
According to their own statements, the present comprehensive inventory is the first of its kind. The researchers found that some of the 40 animal and 44 plant species listed as extinct in the wild in the Red List were incorrectly classified in various respects, so that the number somewhat reduced. Overall, however, they come to a clear conclusion. There are many ways to prevent extinction in the wild or to bring back species that have disappeared there, "and we have to seize them".
"It is a Herculean task to reintroduce all species that are extinct in the wild, which is ultimately the goal of every zoo, aquarium, botanical garden and seed bank worldwide," admits co-author Axel Moehrenschlager of the International Union for Conservation of Nature (IUCN). In view of the climate crisis and the loss of biodiversity, these facilities would become even more important in the future.