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Wildlife Magazine Article
"Ferrets Take Advantage of a Last Opportunity," a Heritage Special Report
by Zenon Mocarski
This article was published in the March–April 2011 issue of Arizona Wildlife Views magazine. Support Arizona's award-winning wildlife magazine — order online.
Life is a series of opportunities, each presenting itself at a different moment in time. How a person handles those special moments can have long-lasting impacts.
Occasionally, opportunities present themselves more than once, providing a chance to possibly right a wrong.
Sometimes, however, when opportunity arrives, you had better take note, for it may never arrive again, and the regret might be difficult to stomach.
Consider if that one opportunity, that critical moment in time, held in the balance just one of two possibilities, survival or extinction: potential removal from the face of the planet.
Imagine the thoughts of biologists faced with such an opportunity, the fate of an entire species squarely on their shoulders. Presented to these biologists was the chance to save the most endangered mammal on Earth: the black-footed ferret.
It’s been a long road for the black-footed ferret, a 2½-foot-long specialist carnivore whose diet is more than 90 percent prairie dog.
The black-footed ferret was thought to be extinct until a small population of 129 was discovered near Meteesee, Wyo., in 1981. The population was closely monitored until a disease outbreak nearly wiped the planet clean of the species. A decision had to be made and the last 18 were captured. Captive breeding efforts began in 1985.
Simply put, the survival of an entire species came down to just seven males and 11 females.
“It’s an amazing story of success when you consider that all the ferrets we have in the wild are offspring of the last 18 captured near Meteesee,” says Jeff Corcoran, supervisor at the Arizona black-footed ferret reintroduction site. “Despite the potential for inbreeding, there have been few genetic changes to this animal.
“It really is quite remarkable.”
The path of the black-footed ferret is that of modern wildlife management; from a time when the connection between animals, habitat and fragmentation was not clearly understood, to the current knowledge base and surveying techniques.
The near-demise of the black-footed ferret was a result of several factors, including disease, prairie-dog poisoning efforts, loss of habitat and habitat fragmentation.
These animals, as specialist carnivores, are directly tied to the fate of their prey. Black-footed ferrets not only rely on the prairie dog for food, but also use the burrows for shelter and to raise their young.
With settlement of the West, habitat was lost as roads, trains and houses began to pop up throughout prairie-dog habitat. Populations of prairie dog and ferrets were fragmented, which made it difficult for both to recover from mortality events, including diseases such as plague and canine distemper.
In addition to these factors, early in the 20th century little was known about how tied the black-footed ferret was to the prairie dog. Considered a pest, prairie dogs were poisoned by the tens of thousands, severely depleting the ferrets’ food supply.
As all the events unfolded, black-footed ferret numbers dropped dramatically.
It didn’t take long for the prairie dog population to dwindle, and because the black-footed ferret is rarely seen during daylight hours, few noticed the impact on its population.
In Arizona …
The success story of this small, endangered carnivore started in 1996, when the state’s Aubrey Valley outside Seligman was confirmed as a reintroduction site. Primarily supported through Arizona’s voter-approved Heritage Fund, the Arizona Game and Fish Department began one of the most successful reintroduction efforts in the nation.
The Heritage Fund, passed by voters in 1990, provided Arizona an opportunity to serve as a reintroduction site for an animal not seen in the state since 1931.
“Recovery of an endangered species like the black-footed ferret is a long-term process,” says Bill Van Pelt, the department’s nongame birds and mammals program manager. “Having a dedicated funding source like the Heritage Fund plays a critical role.”
“When Aubrey Valley was selected in 1996, there were only three other reintroduction sites,” says Jeff Pebworth, wildlife program manager at the department’s Kingman office, 60 miles west of Aubrey Valley. “This is an animal that had been absent from the state for 65 years. The Heritage Fund allowed Game and Fish to be the lead agency in the state’s effort without any cost to Arizona taxpayers. No general funds come to the Arizona Game and Fish Department for managing wildlife.”
And, over the last decade, that funding source has proven fruitful to the black-footed ferrets.
Every year, department staff and a host of volunteers gather in Aubrey Valley to conduct spotlighting surveys (the method used to document the ferrets’ population, reproduction and long-term survival). For the first four years, they were simply long, cold nights in the spring and fall with little reason for excitement. The only ferrets captured were those bred in captivity and released. There was no sign of ferret offspring.
Game and Fish Department personnel remained steadfast in their dedication to the effort, but after four years with no sign of breeding in the wild, “enthusiastic” wasn’t quite the right word to describe the emotions of those involved.
“We were still cautiously optimistic,” says Bob Posey, who supervises the department’s Kingman office. “When we captured seven wild-born ferrets in 2001, everyone was excited. Our efforts were finally beginning to show.”
Those efforts have been substantial, including the dedication of volunteers and other partners who have played a critical role in the recovery of this animal. The work is far from a walk in the park. Spotlighting alone involves a massive effort to cover a lot of territory … at night. As nocturnal animals, black-footed ferrets can be surveyed only during the evening hours using high-powered spotlights that reflect the animal’s emerald-green eye shine.
However, while it is difficult work, the rewards are great.
In just the last nine years, the reintroduction site has reached a population high enough to be considered self-sustaining, meaning no captive-bred ferrets are released in the Aubrey Valley. In 2009, the ferret reintroduction crew documented 60 individual ferrets, followed by a record 96 individuals counted in 2010.
From 18 left in the world to at least 96 in Arizona alone. This figure represents the minimum population, as not all areas are easily surveyed and not all animals spotted are captured. Arizona is playing a vital role in the national recovery effort and is meeting population targets set for the state that could eventually lead to down-listing the species.
For the black-footed ferret, down-listing would mean moving from endangered status to threatened. The ultimate goal, however, would be to attain recovery status and be removed from the federal endangered species list altogether.
“The black-footed ferret is a great example as to why we should not give up on endangered species recovery,” Van Pelt says. “Although ferrets were on the brink of extinction in 1987, we have been able to bring them back to where they now number over 800 in the wild.
“It just takes time, resources, patience and some luck.”
On Sept. 26, 2011, reintroduction sites around the country will be celebrating the 30th anniversary of the discovery of the last known population of wild black-footed ferrets, and Arizona will celebrate its 15th year as a reintroduction site.
While the program has been successful in Arizona, monitoring remains critical. Because this animal has a life expectancy of just three to four years in the wild, black-footed ferret recovery will take time. There’s also the possibility of a disease outbreak similar to the one that nearly claimed the last remaining ferrets in 1985, along with the potential loss of additional habitat.
None of the reintroduction sites, 19 in all, are close together, meaning problems at one site will not impact another. However, the potential to take a step backward is why continued monitoring remains a critical aspect of the reintroduction. If a population drop is seen, it can be documented early and biologists can react quickly to the crisis.
“Our goal, in short, is to put ourselves out of work,” Corcoran says. “It is a long process, but I hope one day to reflect on how I helped bring an animal back from the brink of extinction. I think there are a lot of Game and Fish personnel and volunteers who feel the same way.”
Those interested in helping with spotlighting efforts or wanting more information may contact the black-footed ferret reintroduction crew at firstname.lastname@example.org.
• First to use outdoor, preconditioning pens to acclimate ferrets to the wild, which became standard at all other sites
• First to attempt on-site pen breeding (1997)
• First to attempt spring releases of pregnant females, increasing survival rates
• First successful reintroduction site in Gunnison’s prairie dog habitat
This article was published in the March–April 2011 issue of Arizona Wildlife Views magazine. To subscribe or give a gift, order online.
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