Ferrets and Prairie Dogs: After being nearly wiped out in the early 20th century, the black- footed ferret is making a comeback. It’s taken a complicated conservation effort and a captive breeding program to restore this species to the Great Plains. The health of the ferret is tied directly to the success of prairie dogs— animals that have also had plenty of run-ins with humans. Keeping these two playful, adorable species in good shape is also helping save 130 unique plants and animals in this North American prairie ecosystem.