Black-footed ferrets are one of the most endangered mammals in North America with only an estimated 370 in the wild, according to the World
This is a pretty big deal. When I was a kid in the 1980s, this was one of the most endangered species in the world. It had been declared extinct in 1979, but two years later a small population was discovered in Wyoming. These became the basis for a breeding and reintroduction program, and today there are a few hundred in the wild with more in captive breeding programs.
The challenge with working with such a small captive population is that you only have so many adult female ferrets that can be having kits at any given time. While cloning is more resource-intensive than simply raising a ferret born in captivity, it adds another individual to the breeding pool. If cloning can be streamlined, it could help increase the number of breeding adult ferrets more quickly than through natural means alone.
In this case, one of the first cloned black-footed ferrets has not only made it to adulthood but has successfully given birth to two kits which wouldn't have existed otherwise. Because she was cloned from the cells of a ferret that died in the 1980s, she was able to reintroduce genetic diversity in a species that has suffered a severe population bottleneck. While it remains to be seen whether the kits survive to adulthood--a challenge any young ferret faces--this is a very promising sign.
We can't rely on cloning alone to save this species, though. The systematic destruction of prairie habitats for agriculture and other development, the subsequent loss of prey populations, the introduction of canine distemper from domestic dogs, and secondary poisoning from poisoned prairie dogs and other prey, all have contributed to the precipitous decline of this charismatic little mustelid. By preserving and restoring prairie habitats and their biodiversity, preventing the poisoning of prey, and controlling canine distemper vectors, we can give both birthed and cloned black-footed ferrets a better chance of reestablishing their species in their historic range.