Dozens of slinky, ferocious and rare ferrets are making new homes in Colorado, one year after they were released at a wildlife refuge outside Denver.
The U.S. Fish and Wildlife Service counted 47 endangered black-footed ferrets in October at the Rocky Mountain Arsenal National Wildlife Refuge.
Searchers also found nearly two dozen black-footed ferrets that were born at the refuge — a promising sign for the campaign to bring the animals back from the brink of extinction.
Black-footed ferrets are so rare that scientists came up with crazy-sounding ideas to keep them healthy. In Montana, wildlife officials planned to preserve their main source of food and shelter — burrowing prairie dogs — by distributing vaccine-laced candy from drones.
Here’s a look at black-footed ferrets and an update on the program to save them:
— Endangered Species (@USFWSEndsp) November 7, 2016
How many are left?
Black-footed ferrets were once thought to be extinct. Their numbers plummeted as prairie dogs were exterminated or died from plague. Human development also reduced ferret habitat.
But a small colony of ferrets was discovered in Wyoming in 1981.
About 300 live in the wild at 28 reintroduction sites in several U.S. states, mostly out West, and in the Canadian province of Saskatchewan and the Mexican state of Chihuahua.
Another 300 captive-born ferrets are being prepared for release at six breeding centers.
How do you count ferrets?
Teams searched for 10 nights at the Colorado refuge last month, using lights to spot the telltale emerald reflection from the ferrets’ night-vision eyes.
Once they located ferrets, searchers placed elongated, burlap-covered traps over their burrows. Because the traps resembled part of the burrow, the naturally curious ferrets climbed in.
Searchers could distinguish captive-born ferrets from those born at the refuge because ID chips were implanted in captive-born animals before their release.
The wild-born ferrets were vaccinated for plague, canine distemper and rabies, implanted with a chip and turned loose again. Captive-born ferrets are vaccinated before they’re released.
How many is enough?
The Fish and Wildlife Service has a goal of 3,000 breeding adult ferrets in at least 30 populations in at least nine states. At the Rocky Mountain Arsenal refuge, the goal is about 77 to 120 ferrets, said Nick Kaczor, assistant manager of the refuge.
“Those wild-born ones, man, they were feisty, they were aggressive,” Kaczor said. “You can tell they have that fighting instinct.”