Black-Footed Ferret

A disease called canine distemper wiped out most of the wild black-footed ferrets near Meeteetse in 1985. Biologists were afraid the remaining ferrets would die, so the ferrets were captured and taken into captivity at the Sybille Wildlife Research and Conservation Education Center near Wheatland, Wyoming.

And because of this, the Wyoming Game and Fish Department launched the captive breeding program.

The Sybille ferrets did not produce any young in 1986. But in 1987, eight kits were born. The births proved that ferrets will reproduce in captivity. Forty-four kits were born in 1988, and the number of ferrets grew to 58.

Biologists decided to separate the ferrets to avoid diseases and other problems. Some were sent to a branch of the National Zoological Park near Washington, D.C., and others were sent to the Henry Doorly Zoo in Omaha, Nebraska. The rest stayed at Sybille. The captive breeding program has expanded since then to the Cheyenne Mountain Zoological Park in Colorado Springs, Colorado, the Phoenix Zoo in Phoenix, Arizona, the Louisville Zoological Garden in Louisville, Kentucky, the Metropolitan Zoo in Toronto, Canada.

Today, the zoos remain active in the black-footed ferret's captive breeding program. More than a year ago, budget forced the Game and Fish Department to step out of the lead in the black-footed ferret captive breeding effort. The U.S. Fish and Wildlife Service now operates the National Ferret Breeding Center (the former Game and Fish center at Sybille).

Captive breeding continues. In 1995, 310 black-footed ferret kits were born in captivity. More than 170 survived. In 1996, 311 kits were born. More than 225 survived.

One of the most exciting chapters in the black-footed ferret's story occurred in 1991 when captive-raised ferrets were reintroduced into Wyoming's Shirley Basin. More than 220 ferrets were reintroduced in Shirley Basin from 1991-94. But in 1995, a disease called Sylvatic Plague caused a 60 percent decline in Shirley Basin's white-tailed prairie dog population. And in 1995, an outbreak of another disease called canine distemper hit Shirley Basin.

Despite disease, a small number of the black-footed ferrets still survive in Shirley Basin. And, prairie dogs are doing better, so the Game and Fish Department plans to ask the U.S. Fish and Wildlife Service this year for more ferrets to reintroduce in Shirley Basin.

Black-footed ferrets have also been reintroduced in South Dakota, Montana and Arizona. The ferrets are doing very well in South Dakota and Montana. They were released in black-tailed prairie dog towns. The ferrets released in Arizona were released in Gunnison's prairie dog towns.

The black-footed ferrets themselves are interesting to study, and that's part of the reason why four states are working with them today.

Black-footed ferrets live in and around prairie dog towns. They are loners and are nocturnal, which means they are most active at night.

Black-footed ferrets are predators. Most of their diet is made up of prairie dogs. They live in unused prairie dog holes, or they kill and eat the owner of the hole and then move in. They move around a lot, from burrow to burrow, hunting for prairie dogs. They sometimes travel more than a mile each night. They leave scent to mark their territory which averages 150 acres for a female with a litter. They live alone except during the breeding season, and even then the males and females only stay together until breeding occurs.

Biologists study black-footed ferrets at night, usually with the help of spotlights. A ferret's eyes glow bright green in the dark, and that's how biologists find them to count them. Ferrets spend a lot of time underground, and their eye shine is hard to see unless they are looking directly at the biologist. As a result, ferrets are always hard to find.

Other ways to tell if black-footed ferrets are around is to watch the snow for tracks or trenching. Black-footed ferrets can't throw dirt between their legs like dogs when they are digging. They hold the dirt on their chests when they are digging, and they back out of the hole and leave a furrow of dirt. These trenches are usually made during the winter, perhaps when ferrets are digging after hibernating prairie dogs.

Adult ferrets have a long, thin bodies, usually between 18 and 22 inches long. Their tails are four to five inches long, and they weigh between one and two and one-half pounds.

Black-footed ferret litters are born in May or June, usually in a litter of three or four kits. Young ferrets look like mice when they are born and their eyes are shut. When they are six to eight weeks old, the mother starts taking the kits out of their burrow. Before winter, the kits are on their own, and they leave their home territory and their mother.

Struggles remain for the black-footed ferret. But with help, one of the world's rarest mammals is receiving a boost.