Recognizing Colorado Endangered Species Week
May 10 through May 16, 2020 is Colorado Endangered Species Week. This week is dedicated to the mission of educating the public and working towards the protection of the over 300 plant and animal species that are at risk in Colorado.
Last summer and fall, in preparing a prairie dog colony on the sprawling sand-sage pasturelands of the Walker Ranch for the introduction of endangered black-footed ferrets, Colorado Parks and Wildlife (CPW) conservation biologist Ed Schmal crisscrossed the sun-baked property, installing 50 randomly located wildlife cameras.
The cameras were erected after he and fellow CPW Conservation Biologist April Estep, aided by CPW wildlife technicians and staff, spent many hot summer days walking and riding the 850-acre colony, tossing tens of thousands of peanut butter pellets (dyed to resemble blueberries and laced with plague vaccine) throughout the colony — about 50 pellets per acre — in hopes of protecting the resident black-tailed prairie dogs, and the ferrets that rely on them for food and shelter in their burrows, from the fatal bacterial infection.
“The black-footed ferret is a flagship species,” Estep said. “They are so important. And prairie dogs are equally important. Their burrows host 130 unique plants and animals who depend on that ecosystem and habitat. If we protect prairie dogs and black-footed ferrets, we’re protecting all those other species.”
Similar labor-intensive pellet distribution will take place this summer, for the fourth consecutive year, to slow the spread of the plague and prepare for the possible release of more ferrets later this fall.
But this year, Schmal, Estep and other CPW biologists likely won’t get to see all their hard preparation work pay off with the joy of seeing ferrets run free for the first time and dive into burrows on Georgia and Gary Walker’s ranch.
Plans to release more of North America’s rarest mammal are on hold. The worldwide outbreak of the deadly COVID-19 virus prompted the U.S. Fish and Wildlife Service (USFWS), which oversees national efforts to save the black-footed ferret from extinction, to place them in quarantine until it can be determined if the virus can be transmitted to them by human interaction.
The agency doesn’t know if COVID-19 will join sylvatic plague and canine distemper on the list of fatal threats facing black-footed ferrets, which twice in the 20th century were thought extinct and were listed in 1967 as endangered under the federal Endangered Species Act. They disappeared in the wild due to habitat loss, widespread poisoning of prairie dog colonies and disease.
“Thanks to ongoing studies around the world, we know that SARS-CoV-2 can infect domestic ferrets, so we fear that black-footed ferrets could be susceptible as well,” said Tyler Tretten from the “U.S. Fish and Wildlife Service (USFWS) National Black-footed Ferret Conservation Center in Wellington. “Not only are there relatively few black-footed ferrets in the world, but their low population numbers created a limited gene pool that led to black-footed ferrets becoming immuno-compromised. Therefore, a novel disease like COVID-19 could possibly have catastrophic effects on the population.”
The last official record of a wild black-footed ferret in Colorado was near Buena Vista in 1943. Then in 1979, the last known black-footed ferret in captivity died, and the only ferret species native to the U.S. was believed to be lost.
But in 1981, a small colony, or remnant population, of 129 ferrets was discovered on a ranch near Meeteetse, Wyo. This population, however, soon experienced significant declines due to canine distemper and sylvatic plague. So in 1986, the USFWS captured the remaining 18 wild ferrets for a captive breeding and species preservation program. Those ferrets became the seed population for all subsequent captive breeding and recovery efforts.
CPW joined forces with USFWS, the Utah Division of Wildlife Resources and the Bureau of Land Management (BLM) to restore black-footed ferrets to their native range. Today, Colorado is one of eight states and over 50 total partner agencies involved with the recovery of the species through reintroduction.
Ferrets were first reintroduced to Colorado in 2001 at Wolf Creek, north of Rangely. After dozens were released over several years, that site succumbed to a plague outbreak and collapsed by 2010.
An Eastern Plains reintroduction strategy began in 2013 with the release of 300 ferrets to six Colorado sites over a period of years. In order to be released, individuals have to display their ability to survive in the wild. This training and preparation takes place at the National Black-Footed Ferret Conservation Center in Larimer County.
The restoration of any threatened or endangered wildlife species is deemed successful when Recovery Plan goals are met and released animals begin reproducing on their own in the wild. Black-footed ferrets mate in early spring and give birth to a litter of three or four mouse-sized kits after a seven-week gestation period. In Colorado, the most successful breeding site is at the Rocky Mountain Arsenal National Wildlife Refuge in Commerce City.
Schmal and Estep hope the Walker Ranch might someday enjoy the same success as the Arsenal refuge, where visitors can glimpse black-footed ferrets and wild-born kits, all descended from the 18 remaining ferrets found in 1981.
Given all that has gone into trying to rescue the species, no one wants to risk COVID-19 wiping out any colonies. So this will be a year of maintaining existing colonies for CPW biologists and staff and the Walkers, who have become leaders among Colorado ranchers in allowing protection of prairie dog colonies on vast swaths of their private property. The Walkers first hosted a release in 2013 and 2014 when CPW biologists turned free 107 of the long, slinky, tan, black and white weasels on the property.
The USFWS no-handling protocol also put on hold a project at the National Black-Footed Ferret Conservation Center that was to test whether the ferrets could be equipped with a tiny transmitter that would have broadcast a signal with location information to small receivers installed around a prairie dog colony. The data would be collected by CPW biologists and studied to provide valuable insight into the animals’ location, movements and other information.
“We feel like we know a lot about these animals and how they behave and survive in the wild,” Tretten stated. “But there is always more to learn, especially when dealing with a secretive, nocturnal and fossorial species like this. Telemetry can help us answer some questions that are otherwise virtually impossible for us to figure out on our own. Unfortunately, like the rest of the world right now, our primary concern is COVID-19 at the moment, so we are postponing other research until we feel we have a better hold on this disease.”
But Schmal, Estep and other CPW biologists will push ahead with their work.
And the cameras will provide plenty of new data to study. Each of the 50 cameras snapped three photos per hour, plus a burst of three photos when motion was detected. From the time of the Nov. 18, 2019, release of the latest 14 black-footed ferrets until Schmal downloaded all the cameras in late March, the cameras captured an estimated 8,000 pictures each.
He’s hoping they will provide evidence of the ferrets’ survival and identify burrows where they have taken up residency, and eliminate the need to deploy large teams of CPW staff on nighttime surveillance of the nocturnal ferrets using spotlights.
“This is much less invasive and could prove to be a much more effective way to survey,” Schmal said of the cameras. “Driving prairie at night can damage the grass, and it’s dangerous for staff as well as time-consuming and expensive.”
CPW needs to survey the 900 acres of prairie dog colonies on the ranch because the ferrets don’t always stay put in the burrows where they are released. And catching a glimpse of their eyes in a spotlight isn’t exactly a foolproof method of observing them.
“You have to be passing by a burrow right as a ferret is out and looking your direction,” Schmal said. “Ideally, if we have the cameras in the right place, we’ll be able to identify if they are surviving and which specific burrow they are making their home. We may even be able to glean the presence of predators and get a better idea of the threats they are facing like bobcat, coyote and even owls.”
So he will study film and team with Estep and techs to spread more vaccine across more sprawling prairie dog colonies in the Southeast Region. They will focus on the Walker Ranch and another ranch in Prowers County in far eastern Colorado where they released ferrets in 2017, as well as properties they are preparing for a hoped first-ever release in future years.
Why go to such extremes? Because prairie dogs are incredibly important to the ecosystem. Prairie dogs create habitat for other species, such as endangered black-footed ferrets and burrowing owls. And they are critical to the diets of many animals, including ferrets, raptors, coyotes, bobcats and rattlesnakes.
“Plague vaccine distribution will continue into the future,” Estep said. “Grasslands are such important habitat for black-footed ferrets and so many species.
“We’re still working our way toward recovery. And Colorado is the leading state in conservation of the black-footed ferret. We have multiple sites, we have plague management in place and a funding source. We have a management plan in place that we follow. We have landowners engaged in the process.”
So despite plague that caused a colony collapse in Prowers County, and the threat of distemper and perhaps even COVID-19, Estep wouldn’t even consider giving up on the black-footed ferret.
“I’m still very hopeful,” she said. “Sure, it’s discouraging when you are at a colony hit by plague and you are watching prairie dogs die. But we’ve seen those colonies come back and rebuild. It takes a long time. But it’s worth it.”
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Article by Jason Clay and Bill Vogrin. Jason is CPW’s public information officer for the Northeast Region. He’s based in Denver. Bill is CPW’s public information officer for the Southeast Region. He’s based in Colorado Springs.