DENVER — Thirty black-footed ferrets, among the most endangered mammals on the continent, were released from a breeding facility onto Colorado's eastern plains this week.
On Wednesday, Colorado Parks and Wildlife set free the 30 animals, the only type of ferret native to North America, on land belonging to the Southern Plains Land Trust.
It marked the eighth release site on the eastern plains, CPW said.
The ferrets were raised at a U.S. Fish and Wildlife facility.
The Southern Plains Land Trust owns land designated for prairie wildlife and plants, and has protected more than 56,000 acres. The trust is accredited by the Land Trust Accreditation Commission, which is certified by the State of Colorado, according to its website.
The area is perfect for prairie dogs, which are "an ecologically crucial rodent found only in North America," according to the trust. These critters make up about 90% of the diet of the black-footed ferrets.
The ferrets almost went extinct due to the decline in the prairie dog populations. They were actually thought to be extinct twice, according to CPW, and had been absent since the early 1940s from Colorado's plains. But in September 1981, a small population of the ferrets was found in Meeteetse, Wyoming and researchers found eight black-footed ferrets that could breed.
CPW said all black-footed ferrets that have been born since then are descendants of those original eight animals.
The first reintroductions in Colorado were in 2001 at Wolf Creek, north of Rangely. But a plague killed off that group by 2010.
However, the species persevered and is continuing to rebound thanks to more captive breeding and reintroduction efforts. In 2013, CPW began a program to reintroduce the animals on the eastern plains by releasing 300 ferrets on six sites. While it's too early to call it a success, CPW said they did observe the first natural-born kit in 2015.
CPW said it estimates about 600 ferrets now exist between breeding facilities and wild relocation sites.