The Black-Footed Ferret
According to the Black-Footed Ferret Recovery Program website there are only three ferret species left on earth. These are the Siberian polecat, the European polecat and the black-footed ferret.
The black-footed ferret was once common in its range but its numbers eventually dropped to a devastatingly low 18 animals. Since then, it has recovered to some degree although its survival is still not assured. It is North America's only indigenous native species. It was once common throughout the Great Plains from Alberta, Canada in the north to south west USA. Today this little creature has been reintroduced into several of its traditional areas.
Its fate is tied up with that of the prairie dog. The prairie dog is its main source of food and any factors which affect prairie dog numbers goes on to affect black-footed ferret numbers. The prairie dog is known as a keystone species because the fate of several other species is dependent on whether or not the prairie dog can thrive and survive.
The black-footed ferret is part of the Mustelidae (musk-producing) family. These are found on all continents other than Antarctica and Australia. Mustelids range from the least weasel (barely 2 ounces in weight) to the sea otter which weighs 100 plus pounds. Most mustelids have long, supple bodies, short legs equipped with strong claws, strong jaws and teeth and large skulls. The ears are short and rounded and there are scent glands under the tail. Weasels, polecats, wolverines, badgers, otters and ferrets are all members of the Mustelidae family.
The black-footed ferret is between 46 and 58 cm long with the tail adding another 11 to 15cm to the length. They weigh about a kilo with females being slightly smaller than males. The short, sleek pelage is white near the skin but with darker tips so they appear a yellowy-buff colour. The belly is lighter than the upper parts and the animal is almost white on the throat, muzzle and forehead. The lower legs are black.
There is a very distinctive black face mask across the eyes and the tip of the tail is black. he claws are designed for digging. He has a very keen sense of smell which helps him hunt out prey from underground. The ears and eyes are large. He finds trails at night by the scent from urination and defecation. He also marks his territory in this way.
The black-footed ferret is an obligate carnivore meaning that he relies on one type of animal for the bulk of its food – in this case the prairie dog. Although they also eat insects, birds and other small mammals, they are reliant on prairie dogs for the majority of their food. One hundred prairie dogs a year is the average consumption for an adult ferret and this requires a colony of 125 acres – for one ferret! The burrows of the prairie dog colony are used as shelter from predators and from harsh weather.
This species is nocturnal but is active for only about three hours a day. They spend their time above ground hunting, looking for a mate or finding new burrows. Although the ferret does not hibernate, they decrease the amount of activity and their travelling. Females are believed to be less active and do not travel as far as males. Apart from the breeding season and raising their young, the ferret is solitary.
Gestation is between 41 and 43 days and a litter of generally 3 to 4 kits are born although litters of nine or ten kits have been recorded. The kits are born blind and helpless, weighing 5 to 9 grams. The thin, white hair begins to develop dark markings at about three weeks of age and at five weeks the eyes open. They become increasingly active and develop very rapidly from that point onwards. However they still depend on their mother for food and help till they are about seven months of age. They are sexually mature at twelve months old. The male takes no part in raising the kits.
Ferrets are very playful. The 'ferret dance' sees the ferret hopping backwards with the mouth wide open and the back arched. There are a number of vocalisations. They may hiss when agitated or frightened or chatter loudly to raise the alarm to their fellow ferrets. A whimpering sound is used by the mother to entice the young to follow her and males chortle to females during the breeding season.
While the black-footed ferret itself has not been persecuted on its own accord, farmers and ranchers made concerted efforts to rid their lands of prairie dogs. Underground complexes were ploughed up and the inmates poisoned or shot. Even today, the animals are considered pests in many areas and their destruction continues.
Disease took a huge toll on both prairie dogs and ferrets alike. Introduced diseases such as sylvatic plague (a form of bubonic plague) and canine distemper made huge inroads with whole colonies of prairie dogs being wiped out. There is now a vaccine available which prevents sylvatic plague. All captive ferrets are vaccinated as are any wild ones that can be caught. Natural predators include coyotes, golden eagles, badgers, foxes and great horned owls.
In 1981, the black-footed ferret was rediscovered near Meeteetse, Wyoming after having been believed to be extinct.
Native American beliefs and folklore hold the black-footed ferret in high esteem. Ceremonial robes and tribal medicines and cures make use of the body parts and skins of the black-footed ferret.
A captive breeding program was begun in 1987 when eighteen ferrets were captured. Since that time, over 7,100 kits have been produced at the breeding centre.
By 1991 ferrets were being let loose into western areas of their range. Although results were somewhat mixed, some results have been better than expected. BFFRIT (Black-Footed Ferret Recovery Implementation Team) was set up in 1996 to assist in coordinating the various interested parties.
Because of disturbance and disease concerns the breeding facilities are not open to the public. Those animals not suitable for breeding or release act as education ambassadors throughout the USA. Extensive records are kept of each animal so that genetic diversity can be as broad as possible.
With luck and continued effort, the black-footed ferret may once again be seen around the prairie dog towns of the prairies.