In the hills outside Front Royal, scientists and animal keepers are at work ensuring that endangered species from America and beyond survive. One of their ongoing success stories has been that of the black-footed ferret. WMRA's Randi B. Hagi reports.
In the days of yore, black-footed ferrets thrived on the Great Plains, living in prairie dog burrows from southern Canada to northern Mexico. They're sleek little relatives of weasels and minks, with cream-and-brown fur and a dark mask and paws. By the 1980s, they were thought to be extinct. But then, 18 of the mustelids were discovered on a ranch in Wyoming.
ADRIENNE CROSIER: That population started to decrease in numbers pretty rapidly, and so a small population of animals was brought into human care for the purposes of establishing a breeding program … for reintroduction back into the wild.
Adrienne Crosier is the carnivore curator at the Smithsonian National Zoo and Conservation Biology Institute campus in Front Royal – a 3,200 acre property dedicated to researching and saving species at risk of extinction. Black-footed ferrets are one of 20 species currently in their care.
CROSIER: So, several different things occurred back in the early 1900s. Farmers were actively eradicating prairie dogs from the western landscape … and black-footed ferrets rely on prairie dogs for their housing, but also, it's their primary food source, so with the loss of the prairie dogs, then we saw the loss of the black-footed ferrets.
They're also susceptible to plague, which they get from the prairie dogs and fleas. The species is managed by the U.S. Fish and Wildlife Service's National Black-Footed Ferret Conservation Center in Colorado, in collaboration with the Smithsonian and other facilities. Through their efforts, there are now about 300 ferrets back in the wild.
CROSIER: It's been really successful. We're learning more every year about the ferrets and their biology and how best to manage them. .. We have had a very good year this year. … We had 13 litters born out of 16 females. … That's our goal every year, is to produce as many ferret kits as possible from the females that we have.
This year's litters ranged from one to eight kits each – several females had six or more. Currently, the moms and kits live in indoor enclosures and are monitored closely. The moms monitor the keepers right back, as you can hear in this video recorded by staff.
[Black-footed ferret chatter]
Outside, solo adults are housed in kennels. They're used to hot summers and cold winters on the prairie. We put on shoe covers to prevent tracking in any pathogens from outside.
[shoe covers rustle]
CROSIER: We have some pretty deep substrate, so this is just a nice gravel, dirt mix substrate …
The ferrets like to dig in the substrate, run through tubes, and periscope up from hidey-holes – several poked their heads out of nest boxes as we walked by.
CROSIER: So they're most active at night. They will definitely come out early in the morning and then in the afternoon. A lot of our males, especially at feeding time – they know it's feeding time … and we have some males that always are right there at the door waiting for their food.
This property has a long history of animal husbandry. Ellie Tahmaseb, public affairs specialist, explained it was formerly a U.S. Army Remount Service station, when the military employed huge numbers of horses and mules.
ELLIE TAHMASEB: There were soldiers here, there were a lot of horses here, and it actually also was a prisoner of war camp during World War II for German and Italian soldiers. Fast forward a little bit, the property turns over to the USDA for a cattle research facility, and then in 1970, Theodore Reed, who was the director of the zoo at the time, was looking for a place to breed endangered species that maybe needed a little bit more space, a little bit more quiet than was available in Washington, D.C.
One of their notable ferret residents is Antonia – a clone of a ferret named Willa. She was one of the last individuals captured in the wild in the late 80s. Willa died without reproducing, further exacerbating an extreme genetic bottleneck. But her genetic material was preserved, replicated into Antonia, and now passed down to Antonia's offspring. She's had two successful litters, but sadly, she lost all her kits this spring.
CROSIER: We, of course, try to maximize the gene diversity we have in our managed population as much as possible. … In August, population managers and genetic advisors will look at the entire population in human care and determine which animals, genetically, should stay back for the next year's breeding, and which animals should go to the release population.
The ferrets with the most unique genes are typically kept in the Smithsonian's breeding program. The ones approved for release out west go to the Conservation Center in Colorado, where they have to prove they can hunt live prey.
CROSIER: We also do feed live rats to the kit groups when they're a bit older. We wait until they're around eight weeks old … and that helps them learn how to hunt. They learn that from mom, and then that just sets them up for success a little bit better when they do go through that release program.
[ferret chattering]
The nest of one mother, Mizuno, and her six kits has a livestream camera feed on the Smithsonian's website, where you can watch the babies play, feed, dig, and generally learn how to be ferrets – skills they may need some day out on the Great Plains.
