What do North Carolina' s red wolves, the Eurasian beaver and Przewalski' s horse have in common?
All of them went extinct in the wild and all of them came back, thanks to reintroduction pro-grams.
Conservation scientists use translocation and captive breeding(圈养繁殖) to re-establish animal populations that have died out in the wild--either entirely or in certain areas. Reintroducing extinct-in-the-wild animals to their native territories can be a double win: helping to restore dam-aged ecosystems, as well as increasing population numbers.
But setting a species loose in the wild is a risky balancing act. Reintroductions often take years and involve multiple stages. Before bringing back a species, conservationists have to evaluate the threat level—both to and from the animal—and the role it played in the ecosystem. In places where wild populations have died out more recently, there' s a better chance of success. The less time that has passed, the more likely that environment is the same as when the species went ex-tinct. But scientists still need to address the reason why it went extinct in that environment to be-gin with.
Reintroduced animals can have a positive impact on the landscape, but how fast this happens depends on the type of animal and how damaged the environment is. Herbivores(食草动物) can make a significant change relatively quickly, while predators tend to be reintroduced slowly and carefully. Although they can be useful for managing pest species, conservationists have to ensure they don' t overhunt or threaten other vulnerable animals.
A 2020 study highlighted species reintroduction as one of the most effective ways to save endangered animals. The study estimates that conservation action between 1993 and 2020 saved up to 48 species of birds and mammals from extinction, and that the rate of extinction would have been three to four times higher, during that period, without those efforts.