Ferrets Reintroduced in Denver

Returning to Colorado today, I learned that my arrival coincided with the introduction of 30 black-footed ferrets at Rocky Mountain Arsenal NWR, in northeast Denver.  Renowned as the most endangered mammal in North America, black-footed ferrets were thought to have become extinct by the 1970s (due to habitat loss, disease and the removal of prairie dog colonies) until a colony of ferrets was discovered in Meeteetse, Wyoming, in 1981 (thanks to the scavenging activity of a farm dog).

Since 1986, a captive breeding program, coordinated by the National Black-footed Ferret Conservation Center near Carr, Colorado, has been conducted at the Center and at a number of zoos across the country.  Beginning in 1991, ferrets were reintroduced to the Shirley Basin of Wyoming, followed by sites in Montana and South Dakota; later, colonies were reintroduced in Colorado, Utah, Arizona, New Mexico, Kansas, Saskatchewan and Mexico.  To date, more than 1000 black-footed ferrets have been reintroduced to their former range; breeding success has been documented within some of the colonies but close monitoring continues.

Once a production center for munitions, chemical weapons and insecticides, the Rocky Mountain Arsenal was selected as a Superfund Cleanup Site and has since become an urban National Wildlife Refuge, hemmed in by Metro Denver and the Denver International Airport.  Plenty of shortgrass prairie and large colonies of black-tailed prairie dogs make the refuge an ideal location for the ferrets; the latter are solitary, nocturnal hunters, known to feed almost exclusively on prairie dogs (supplemented on occasion by mice and ground squirrels).  Members of the weasel family, black-footed ferrets are the only ferret native to North America.

Data for this post was obtained from the U.S. Fish & Wildlife Service