Back in the Field to Save Black-Footed Ferrets
Before this spring, it had been almost eight years since I had done black-footed ferret fieldwork! So I was excited to head back into the wild in March. After all, beyond helping a critically endangered species, there’s nothing like being out on the prairie in the middle of the night.
Some background on the species: the black-footed ferret is one of the rarest mammals in North America. In the mid-1980s, there were fewer than 20 black-footed ferrets in the world. Thanks to an intensive, shared conservation effort, this small founding population has grown to more than 8,000 individuals over roughly 30 years.
A recovery plan managed by the U.S. Fish and Wildlife Service has been reintroducing ferrets to the wild since 1991. There are now 21 reintroduction sites across the Great Plains and about 300 to 400 ferrets in the wild.
Over the years, though, we have observed declining fertility in the non-wild black-footed ferret population. The experts involved wonder whether this is an environmental effect…or, despite our best matchmaking efforts, a first sign of inbreeding depression. To begin to answer the question, the Phoenix Zoo Conservation Fund offered some funding to study wild black-footed ferrets to determine if their fertility rates were also decreasing and find out what diseases the ferrets encounter in the wild.
That’s what brought me back into the field, where I worked with Travis Livieri from Prairie Wildlife Research and Debbie Grossblat, D.V.M., from the National Black-Footed Ferret Conservation Center, to collect samples from wild black-footed ferrets in Wind Cave National Park just outside Hot Springs, South Dakota.
Midnight Check-ups at Wind Cave National Park
This ferret field project was my first time visiting Wind Cave National Park. I’ve conducted black-footed ferret fieldwork in Mexico, Arizona, Colorado, Utah, Wyoming, Montana and other sites in South Dakota. It’s always exciting to see this critically endangered species in a new area.
Wind Cave did not disappoint. Named for the world’s sixth-largest cave system, it’s a mixture of rolling grass hills with dense forest. It has large populations of elk and bison as well as a large prairie dog town, which makes it perfect for black-footed ferrets.
It was dark by the time we pulled up to our working trailer, although had such a great full moon that we practically didn’t need a flashlight. Debbie, Travis and I immediately got to work setting up all the equipment. And there was a lot to get ready!
When we catch and release a ferret, we take all the samples we can think of, never knowing if we’ll get our hands on that ferret ever again. We take flea and tick samples for disease analysis. We take hair for genetics and stress analysis. Blood is collected for disease-exposure testing and overall health screening. We also collect semen for fertility assessment in the males, and I cryopreserve the samples so we can use it for artificial insemination. That’s a way to bring the genes back from the wild without bringing in the ferret.
We trap our first ferret at 1 a.m. It’s a female, and she looks great, long and sleek. Even though it’s a rough life in the wild, she is beautiful and fit. This night we get six ferrets total, and I’m out in the field until 11 a.m. cryopreserving samples. Then I crash back in the National Park Services’ housing and try to get some sleep before we do it all over again.
Seeing Signs—and Scratches—of Breeding Season
The second night, we head back into the field after a late dinner. Some folks had spotted a female mountain lion with cubs, but we couldn’t find her. So Debbie and I set up the trailer and waited for ferrets to be brought to us.
Four ferrets are trapped, and we collect samples from them. We are seeing a lot of wounds on the males. It’s the beginning of breeding season, and the males are probably trying to set up territories around the females. They’re predicting poor weather conditions for Monday night, so we try to make the most out of tonight.
A Break with Biology Students
The wildlife biology class from Dakota College at Bottineau was visiting Wind Cave on their spring break. Travis and I met with the group to talk about our work with black-footed ferrets, sharing what we were doing at the National Park. We also went on a tour of the park’s namesake cave with them. The students got to release one of our BFFs and went spotlighting too, shining a light into the evening to locate the ferrets by their eye shine. The group was mostly composed of football players, and they asked plenty of interesting questions about what we were doing and why the ferret was endangered.
Another highlight: the morning after I was served one of the largest pancakes in my life. It was bigger than the plate! The Hot Springs locals were laughing at us as we photographed this monstrous breakfast item. But we needed a hearty breakfast to help us sleep!
Spotting Ferrets at Another Field Site
After another successful night spotlighting (we collected samples from a total of 12 black-footed ferrets at Wind Cave National Park), we decided to move to another ferret reintroduction site that was approximately two hours away in Grasslands National Park and Badlands National Park.
After loading up our truckload of equipment and supplies, we drove northeast. Then we unloaded everything at the U.S. Forest Service headquarters in Wall, South Dakota (famous for its Wall Drug store), took a cat nap (we had been up for 24 hours straight) and then got dinner before we started all over again.
It was around 3:30 a.m. when the first black-footed ferret was trapped. By the end of the evening, we had collected samples from two female ferrets. The next night was our last night in the field, and we spotted two male black-footed ferrets as I headed to the airport, a nice ending to a long-overdue visit to the field.
Overall, it was a successful trip, with us collecting samples from 16 black-footed ferrets from three reintroduction sites! It was great to be on the prairie again; besides ferrets and prairie dogs we saw pronghorn antelope, mule deer, bison, porcupine, cotton-tailed rabbits and bighorn sheep. I was able to explore Wind Cave, a reintroduction site I hadn’t seen before, and visit friends at Conata Basin and Badlands! More than that, though, we gathered a wealth of data, information from the wild that will help us continue to find the best ways to conserve this critically endangered species.