The following is the latest in an ongoing series of blog posts about the Black-Footed Ferret Recovery Program, which strives to save one of the most endangered mammals in North America from extinction. Rachel Santymire, Ph.D., Director of the zoo's Davee Center for Epidemiology and Endocrinology, has played a key role in monitoring fertility among the captive and wild populations managed by a coalition of conservation partners across several Great Plains states. You can read more about her contributions in the feature article “Notes from the Underground” in the spring 2017 issue of Lincoln Park Zoo Magazine. Rachel also blogged about recent field work in this “Survival of the Fittest” post and this “Dog Days with the Cheyenne” post.
It’s been 11 years since I ventured out to Vernal, Utah, to find the elusive black-footed ferret. Initiated in 1999, the Coyote Basin reintroduction site (pictured in above photo) located near here received captive-born ferrets for a few years, and its wild population has persisted for almost two decades. From 2004–2006, our team assessed the health of 20 ferrets from this population. Now, in March 2017, we're back, hoping to determine how the population has changed! I'm joined on this trip by Travis Livieri, Executive Director of Prairie Wildlife Research, and Dr. Kevin Castle from Wildlife Veterinary Consulting in Fort Collins, Colorado. We're also working with Brian Maxfield, who has overseen this site from more than 15 years as a Wildlife Conservation Biologist with the Utah Division of Wildlife Resources.
Since my last visit, the town of Vernal has grown mostly because of the oil and gas industry. Coyote Basin is close enough that we can easily get to Vernal’s 24-hour Walmart and Starbucks for basic necessities and a caffeine boost. We often work at very remote Great Plains reintro sites, so we're spoiled on this trip.
Coyote Basin and a nearby ridge, Snake John Reef, have undergone some changes in habitat quality over the years. Unfortunately, an outbreak of sylvatic plague—an introduced disease that has killed ferrets and their prairie dog prey over the last century—is suspected to have gone through the population. That, along with tall grasses that sheep haven't been able to reduce, has made it very difficult to find ferrets.
After three nights of spotlighting, we have seen no signs of ferrets. In fact, all that I have seen is a sea of sheep heavily guarded by dogs of the Anatolian shepherd breed. Brian and his crew offered to try to find ferrets for one more night, but we decided to cut our losses and head to Colorado to try another reintro site.
Utah has incredible landscape diversity with 43 state parks. Our trek to Colorado also took us past Flaming Gorge Dam and across southern Wyoming. Not a tree for miles. It takes a while to get used to if you’re from the East Coast like me. However, this habitat is perfect for prairie dog towns and ferrets.
On St. Patrick's Day in Colorado, I pull on my holiday-themed socks and head out to collect samples from the captive, male black-footed ferrets at the U.S. Fish and Wildlife Service’s (USFWS) National Black-Footed Ferret Conservation Center. I have been coming out to this breeding facility for 12 years. This spring we have set up our research to directly compare the fertility and health of wild and captive ferrets. To do so, we are non-invasively collecting biological samples from both captive and wild populations at the same time—sometimes on the same day.
Santymire (left) IDs a black-footed ferret in Colorado with a microchip scanner during a non-invasive medical exam. Biological samples collected and stored during exams help scientists research fertility declines and other issues in wild and captive populations.
I worked with staff at the center and evaluated male ferret fertility during the day. At night, Travis and Kevin went spotlighting for wild ferrets in the Soap Stone prairie lands surrounding the ferret center. Serendipitously, a staff member at the center spotted a wild ferret from her office window one day. John Hughes, a biologist at the center, set a safe trap on the ferret’s burrow and that afternoon the ferret was trapped! I had just finished collecting samples from captive males. Now I set up my equipment in the center's quarantine building. Dr. Della Garelle, a contract veterinarian who has helped us with our biomedical survey in the past, helped me collect blood and semen samples from this wild male ferret.
After another two nights of spotlighting only one more ferret was seen, but not trapped. Luckily, we got a reading off of her microchip (we use them in the same way dogs are individually ID'd by pet owners) and found out that our wild male friend has a lady ferret friend in the area. It’s the breeding season, and they have my blessing.
By the way, Colorado is also home to urban ferrets! Finally, my two research worlds collide.
Just outside of Denver, near the Denver International Airport, lies the Rocky Mountain Arsenal (RMA). It was a United States chemical-weapon manufacturing site where napalm, sarin and several pesticides were created and dumped. It became a Superfund site and was being cleaned up when a bald eagle nest was found there in the early 1980s. Since then, it has been a National Wildlife Refuge managed by USFWS. The prairie has been beautifully restored, and in 2015 ferrets were reintroduced here.
It’s a very exciting site for me and my research. It's one of the few sites that still has captive-born ferrets and first-generation wild-borns. I can collect samples and answer my question about the impacts of environment on ferret fertility and health.
I had help again from Travis and Kevin, as well as Dr. Danielle Buttke from the National Park Service and a biologist at RMA. After collecting and cryopreserving samples from captive ferrets, we drove down to RMA, set up and started spotlighting for ferrets.
Much more successfully than in Utah, we collected five ferrets the first night and seven more the next night. All in all, I assessed the fertility of 15 captive males and 12 wild males, cryopreserving a total of 20 samples to be stored for future use in the Black-Footed Ferret Genome Resource Bank, housed at the Smithsonian Institute.
Ferrets are an amazing species. Given a healthy environment, they can be successful. However, the people that work on this recovery program are just as amazing. They are passionate and dedicated to restoring the Great Plains to its natural, splendid state. Thank you to all of them for their hard work!
Rachel Santymire, Ph.D., is director of Lincoln Park Zoo’s Davee Center for Epidemiology and Endocrinology.