FORT Researchers Meet the Challenges of Re-establishing the Endangered Black-Footed Ferret

More than twenty years have passed since the discovery, in 1981, of the last known wild population of black-footed ferrets near the small town of Meeteetse, Wyoming. This secretive, nocturnal member of the weasel family was thought to be extinct, or nearly so. The black-footed ferret was known to be very dependent on large colonies of prairie dogs, but little else was known about these rarely seen animals.

What started with excitement over their discovery, however, soon degraded into a frantic effort to save the last of a dying population. Distemper and plague, both introduced diseases, were discovered on the prairie dog colony that supported the ferret population. Between 1981 and 1987 the Meeteetse ferret population dropped from an active community consisting of many family groups to only 14 individuals captured to save the species. Those 14 animals became the future of the black-footed ferret recovery program.

The initial research focus in 1981 was on learning about and recovering these last remaining free-ranging ferrets. From 1987 to 1991, the focus of research changed to questions on captive breeding techniques and what constitutes suitable habitat for eventual reintroduction of the ferret. Studies were conducted to standardize methods for measuring prairie dog populations. Surrogate Siberian polecats imported from the Moscow Zoo were used to determine effective monitoring techniques in preparation for the eventual release of the captive-born and raised black-footed ferrets. The Siberian polecat is the closest known relative to the black-footed ferret. Behavioral studies were also conducted to determine what rearing influence or conditioning might be required to increase survival of reintroduced ferrets.

The first reintroduction was conducted at Shirley Basin, Wyoming , in the fall of 1991. Ferret researchers participated in the reintroductions, using custom-made radio telemetry systems to document the fate of the captive-born and raised, reintroduced ferrets. Survival was poor for the first year of reintroductions, so between 1992 and 1998 program researchers studied captive rearing and reintroduction techniques and developed minimal standards for reintroduction habitat. This was a massive effort requiring hundreds of biologists, technicians, and volunteers from many different agencies, countries, and backgrounds. The information gleaned from this work standardized much of the captive-rearing and reintroduction techniques for the black-footed ferret recovery program.

In 1999, research efforts were once again directed toward a field study on translocation and management of re-established ferret populations. With only 14 animals founding the entire black-footed ferret population, genetic management was essential. Moving wild-born young ferrets between populations had to be studied to determine if they could be moved successfully and whether they survived better than captive-raised animals upon translocation. Research concluded that wild-born translocated black-footed ferrets survive much better than their captive-reared counterparts. Translocation of young wild-born ferrets is now considered a viable option for genetically managing wild populations.

Beginning in 2000, the research emphasis changed once again. Although ferrets had been introduced into Montana, South Dakota, Wyoming, Colorado, Utah and Arizona, only the South Dakota populations were flourishing. South Dakota was the only state that had not recorded the presence of plague and fluctuating prairie dog populations. The decision was made to focus future research on understanding how plague was affecting small-mammal populations and the prairie dog ecosystem. The cooperative project on plague has included partners and cooperators with USFWS, USGS, CDC, BLM, NPS, USFS; state agencies in Colorado, Utah, Wyoming, Montana, and Arizona; the University of Virginia, Colorado State University, University of Colorado, Kansas State University; and organizations like the Denver Zoo, the Turner Endangered Species Foundation, the Russian Academy of Sciences, the Chinese Academy of Sciences, and many others. This research has begun to unravel the mystery of how plague operates in the wild.

FORT Scientist Key to Ferret Recovery The constant in the black-footed ferret research program has been USGS scientist Dean Biggins. He was there as a USFWS researcher in 1981 with the discovery of the black-footed ferret colony, and he captured one of the last free-ranging ferrets when captive breeding was the only hope. He has designed countless studies to help resolve the seemingly insurmountable problems of ferret re-establishment. Dr. Biggins now designs and conducts studies on the effects of plague on ferret habitat. His dedication and that of the hundreds of other biologists, cooperators, technicians, and volunteers on the black-footed ferret project over the last 20 years are part of the reason there is now hope for the recovery of this endangered animal.

Research begun by then-U.S. Fish and Wildlife Service biologists Dean Biggins and Jerry Godbey continues at the USGS Fort Collins Science Center (FORT) in Fort Collins, Colorado, where these two scientists still lead this long-term research project. As in 1981, project researchers today still focus on learning about the black-footed ferret and the ecosystem that supports it. The program continues to conduct studies addressing the complex problems of re-establishing a critically endangered species in the West.

For more information contact: Jerry Godbey

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