The black-footed ferret, Mustela nigripes, has lived on the great plains of North America since mammoths marched across the continent and were underfoot as herds of millions of bison roamed the “wild west.” It relies on the prairie dog for food as well as shelter, taking prairie dog burrows as homes. During the first half of the 20th century misguided predator control campaigns and efforts to eradicate prairie dogs from farm and ranch land caused the black-footed ferret to nearly go extinct – to the point that for several years no one could find a living ferret, and feared they were already gone.
In 1981, the world’s last population of ferrets was discovered on ranchland near Meeteetse, Wyoming. Disease threatened the survival of the last few ferrets in the wild; a landmark decision was made to initiate a captive breeding program. The Wyoming State Game and Fish Department and US Fish and Wildlife Service elicited the help of Association of Zoos and Aquariums specialists to save the species from extinction. From 1985-1987 the last wild ferrets were captured to begin the breeding program run by what is now called the Black-footed Ferret Recovery Implementation Team.
Since then the recovery team’s facilities have bred more than 8,300 ferrets, representing more than 15 generations. Today ferrets have been reintroduced to more than 19 sites in the wild, a major success for the recovery team. The USFWS is highly invested in the long-term future of the ferrets, and has high interests in overcoming the challenges facing the ferret, which include invasive diseases (sylvatic plague and canine distemper) and the potential for “inbreeding depression” which can reduce fertility and survival. Inbreeding depression is a serious concern long term; all living ferrets are descended from just seven unrelated individuals.
Genetic rescue through advanced reproductive technologies can be guided with genome studies for the first time thanks to resources newly generated for the domestic ferret, a close cousin of the black-footed ferret. The domestic ferret has been a model organism for studying human health. To enhance research in medicine, the Broad Institute has sequenced the full genome of the domestic ferret and is studying the genetic diversity of domestic ferrets. Cloning domestic ferrets has become routine for biomedical research and opened the door to use genome-editing tools to study gene function. These tools for the domestic ferret unlock the ability to quickly and efficiently study the black-footed ferret genome, and perhaps turn 30-year-old cryopreserved cells into living ferrets, adding lost diversity to the breeding program.