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Rescuing the Black-Footed Ferret

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SHOW 305: Rescuing the Black-Footed Ferret

A combination of disease, disappearing range land and vanishing prey had pushed the black-footed ferret to the brink of extinction by the early 1980s. Fewer than two dozen black-footed ferrets were alive in the U.S. in 1985, when biologists rounded up the rest for an ambitious reintroduction program. FRONTIERS joins biologists in Wyoming as they breed ferrets in captivity and train them to hunt their primary source of food -- prairie dogs.

Curriculum Links
Activity: Ferret Survival Game
Report From the Field: Patrick Hnilicka, Field Biologist



weasel family,
endangered species,
animal behavior


As you see on FRONTIERS, setting up and maintaining a reintroduction program for an endangered species is not easy. The mortality rate for black-footed ferrets released into their natural habitat is very high (about 90%). You can create a game that reveals some of the challenges involved in helping an endangered species make a comeback.

Rules of Play
  • Working in teams or small groups, create a game that will show what the endangered black-footed ferret is up against. Use poster board for the game board. Draw a ferret trail that winds its way through a prairie dog town; the trail should include 60 to 80 squares. Branch the trail in several directions if you wish. The main objective is for the ferret to get from the "Ferret Farm" starting box to the "Congratulations" (finish) box at the end of the trail.

  • Decorate your game board with drawings or photographs of ferrets, their predators and scenes of ferret habitat. Make instruction cards (see below) and paste them randomly, face up, along the trail. Leave some squares empty as free spaces. You'll need 20 game pieces to represent the ferrets (use pennies, checkers or other small tokens). Roll a die or construct a spin wheel from cardboard to determine the number of spaces you should move with each turn. Work with two or three other students to see how many ferrets you can get through the course to survive. Remember, in reality, most do not.

  • Place the used game pieces into piles marked "winners" and "losers." Calculate the percentage of ferrets that survive after 20 game pieces are used. Use survival information from other groups to determine the total percentage of survivors for your class. Trade boards with other groups and try their designs. What do you think Charles Darwin meant when he claimed that "survival is accomplished by the fittest"?

  • Write these instructions on individual cards that fit the spaces on your ferret trail. Make up others and add them to this list.

    • START. Ferret Farm. This is where all good little ferrets start!

    • Steal a prairie dog steak from your neighbor. Munch quickly and take an extra turn.

    • Stupid prairie dog accidentally jumps in your mouth. Munch heartily while you move ahead 5 free spaces.

    • Eat a delectable, fat prairie dog. Move ahead to the next free space, roll the die and take an extra turn.

    • Munch a prairie dog burger with mouse fries. Take one more turn.

    • Meet the wrong end of a badger. Lose 1 turn so you can heal.

    • Find an empty prairie dog burrow. Roll the die and take an extra turn to escape, but move backward.

    • Bobcat scares you. Run back 5 free spaces or to the Ferret Farm, whichever comes first.

    • Rattlesnake gets into your burrow. Roll the die and take an extra turn to escape, but move backward.

    • Capture and eat a scrawny field mouse. You're still hungry. Move back 2 free spaces.

    • Too much snow to hunt. Can't get out of your burrow. Lose 1 turn.

    • Prairie fire! Run for your life backward 5 spaces.

    • Duck! Where'd that shot come from? Hide for 1 turn.

    • Defective prairie dog burrow caves in. Lose 2 turns while you dig out.

    • Most of the prairie dogs were poisoned! You can't find dinner. Lose 2 turns while you starve.

    • You ate a poisoned prairie dog. You're out.

    • You become owlfodder. You're out.

    • You are the main meal at a bobcat barbecue. You're out.

    • Coyote chews you. You're out.

    • You are the main course at the eagle eatery. You're out.

    • You become hawk hash. You're out.

    • FINISH. Congratulations! You survived a year's worth of ferret hazards.

  • In this activity, students construct a board game that simulates the many hazards the black-footed ferret confronts. Suggested instructions for game cards are included, but encourage students to come up with additional directions. This creative, open-ended activity will give players a sense of the many challenges and hardships encountered by a species living in the wild. Data collected from various games can be used for a variety of mathematical and statistical comparisons.

  • Ferrets -- as well as their cousins, the minks, skunks, otters, badgers, wolverines and fishers -- are all members of what family? (weasel) The black-footed ferret (Mustela nigripes) once roamed the prairies, helping keep the prairie dog population in check. The prairies attracted ranchers, who in turn exterminated the prairie dogs that were competing for the same appealing space. By the early 1980s, loss of habitat and their primary food source (prairie dogs) had pushed the black-footed ferret to the edge of extinction. Not only are prairie dogs the primary food for ferrets, but the ferrets live in the prairie dogs' burrows.

  • Present plans call for ten colonies of ferrets to be established in the western United States. Compare the ferret project with other programs targeted at endangered species, such as the red wolf in North Carolina, the California condor, the caribou in Maine and the Channel Island fox (Show 303). What challenges are unique to this species?

  • Photocopy an unlabeled map of the western United States. Direct students to identify each state. Assign a research project to identify the region where prairies once existed; compare to existing prairies. In what states would prairie dogs and ferrets be found? (the ferret's range extended from the foothills of the Rocky Mountains eastward through the grasslands of Oklahoma, Texas, Kansas, Nebraska and the Dakotas)

  • Do any of your students have ferrets as pets? Although the black-footed ferret is protected by law, European (domestic) ferrets are sold as pets. These animals are intelligent and very curious. They tend to explore where they shouldn't and pack a nasty bite when frightened or provoked. Owners report them to be quite lovable, luxuriously soft, mischievous and good companions.

  • Field biologist Patrick Hnilicka (see "Report From the Field") tells how canine distemper nearly wiped out the black-footed ferrets, believed to be extinct until l981, when a rancher's dog found a dead one in Wyoming. The ranchers didn't learn what it was until they took it to the taxidermist. Biologists began to arrive on the scene, and the rest is history. Hnilicka explains, "A few years later, an epidemic of canine distemper killed almost all those ferrets. The species was saved when the healthy ferrets were captured. All the ferrets alive today originated with that one colony." Today, before ferrets are released, they are vaccinated against distemper; right now, researchers are working to develop a long-term vaccine for both captive-bred ferrets and those caught in the wild.


When we first see Patrick Hnilicka on SCIENTIFIC AMERICAN FRONTIERS, he is using a transecting wheel to survey a prospective home for black-footed ferrets that will later be released into their natural habitat. "This is a simple technique," explains Hnilicka. "You walk through a prairie dog town counting active burrows within a nine-meter transect [sample area]. Using data collected from the sample, you figure out how many prairie dogs occupy a given site. You compare sites and choose the best one for a ferret colony."

Working on the black-footed ferret project is "almost a dream come true" for Hnilicka, who enjoyed raising domestic ferrets as a kid. Hnilicka's interest took him from his native Illinois to the University of Wisconsin at Stevens Point, where he studied wildlife management. Two years later, when he learned of a job opening with Wyoming Game and Fish on the ferret project, Hnilicka applied immediately, got the job, and moved west.

Hnilicka is optimistic about restoring the black-footed ferret. His greatest worry is canine distemper, a highly contagious disease that can wipe out an entire population of ferrets.

For those who work with endangered species, field biology is a year-round job. Habitat work occupies the late spring and summer; in the fall, a new batch of ferrets is released; spotlighting -- looking for released animals -- is done throughout the summer and fall. When the snow starts to fly, Hnilicka heads back to the office for about six months, but does get out to the ferret homes during the winter months for a bit of snow tracking. Beneath the snow, in abandoned prairie dog burrows, the black-footed ferret is quietly making a comeback.


Scientific American Frontiers
Fall 1990 to Spring 2000
Sponsored by GTE Corporation,
now a part of Verizon Communications Inc.