California Department of Fish and Wildlife

Ferrets - Biology and Uses

Introduction Table of Content Ferret Bibliography Population Estimates
Ferret Survey Biology and Uses Ferrets in the Wild World Distribution
California's Concerns Native Carnivores Other Mustelidae Tables

BIOLOGY AND USES OF THE FERRET

  1. TAXONOMY
  2. DESCRIPTION
  3. BIOLOGY, PHYSIOLOGY, AND DISEASES
  4. HISTORY OF FERRETS IN THE U.S.
  5. USES OF THE DOMESTIC FERRET
    1. Hunting Game and Rodents
    2. Lab Animal
    3. Fur Animal
    4. Pet
    5. Ferret Breeding in the U.S.
    6. Hunting Skills of Pet Ferrets
  6. OTHER CARNIVORE SPECIES USED AS PETS

TAXONOMY

The domestic ferret is a form or subspecies of the European polecat , Mustela putorius. The polecat is native to the woodlands, pastoral areas, and wetlands of Europe. King (1990) wrote, ". . . the ferret and European polecat belong to the same biological species," and "Ferrets are fully interfertile with M. putorius and have exactly the same karyotype . . ." Also, Wellstead (1981) reported that “They interbreed readily, the offspring are all fertile and their chromosome count is identical." [Links: description of the European polecat].

Other English vernacular names for the domestic ferret include ferret and European ferret. Western polecat is another name for European polecat. Fitch is a name sometimes applied to domestic ferrets and to wild polecats.

The Smithsonian Institution's U.S. National Museum, Walker's Mammals of the World, and Revised Checklist of North American Mammals North of Mexico, 1997 (Jones, et al.), include the domestic ferret in the species Mustela putorius, and they use the name furo (i.e., Mustela putorius furo) to denote the domesticated form or subspecies. However, the name Mustela furo is often used by the public and many biologists. Others use Putorius furo. The Zoological Society of London's Zoological Record includes the name Mustela furo in its 'experimental' animals list. Mustela putorius furo, Mustela putorius form. furo, Mustela furo, Putorius putorius furo, and Putorius furo are used by various authors in the Zoological Record.

The scientific names Mustela putorius furo, Mustela putorius form. furo, Mustela furo, Putorius putorius furo, and Putorius furo are alternative names used to describe the same animal, the domestic ferret. Any of these names could be applied to this animal, whether it is a ferret in the wild in New Zealand, a ferret kept as a pet in an American city, a ferret used in chasing rabbits from their warrens in Ireland, a ferret raised for its pelt on a fur farm, or a ferret used in disease testing.

Mustela is the genus name. An example of a different species of this genus is Mustela nigripes, the black-footed ferret that is native to North America. [Note: Mustela furo and Mustela putorius furo are abbreviated M. furo and M. p. furo.]

The genus Mustela includes the polecats, ferrets, weasels and many other species of small, fur-bearing carnivores found around the world. "Within the genus Mustela, ferrets belong to the subgenus Putorius, from which there are only three extant species: M. putorius, the European polecat; M. eversmanni, the Siberian, or steppe polecat; and M. nigripes, the black-footed ferret. The European polecat lives in open forests and meadows, and is thought to be the ancestor of the domestic ferret. The Siberian polecat looks nearly identical to the black-footed ferret and leads a similar life on open grasslands and semi desert regions across Russia, China and Siberia." - Black-footed Ferret Recovery Implementation Team

Polecats and weasels, together with badgers and otters, are classified in the Family Mustelidae, (species list). Skunks have long been classified in the mustelid family, but new genetics work (Dragoo and Honeycutt, 1997, J. Mammal., 78(2): 426-443) supports separation of skunks into their own taxonomic group, Family Mephitidae.

The Families Viverridae and Herpestidae (often grouped together into one family, Viverridae) are represented by a diversity of small carnivores.  Some of the herpestids, which include the mongooses, are similar in many respects to mustelids. The Egyptian mongoose, Herpestes ichneumon, (phot o / description) was important in the re ligion of the ancient Egyptians, and depictions of  it have been erroneously interpreted by some as being evidence of ancient domestication of the ferret.

Links:

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DESCRIPTION OF THE DOMESTIC FERRET

Size

Domestic ferrets weigh from 1 to 5.5 pounds (0.5 to 2.5 kg). They weigh somewhat less than chihuahuas and weigh much less than most house cats. Their length, including the tail, may be 17 to 24 inches (44 to 60 cm). The male is about twice as large as the female.

Ferrets are as large as, or larger than, nearly half of California's native terrestrial carnivore species (Table 1). About the same size as minks, ferrets are larger than either of the two weasel species—long-tailed weasel and ermine—that naturally occur in California. Long-tailed weasels native to parts of California are similar in facial markings to some ferr ets, but long-tailed weasels are much smaller, weighing one-half to one pound (0.3 to 0.5 kg).

Ferret Colors and Patterns

Domesticated ferrets have been selectively bred for a variety of coat colors, including albino. Some are similar to that of the European polecat (photo).  Various colors and patterns have been developed for ferrets used as pets or fur animals. White ferrets (photo) have long been used in hunting rabbits, such as in the practice of falconry. Show standards for ferrets have been adopted by the Ameri can Ferret Association, Inc.   Ge netics of coat color in ferrets is described by Dr. J. McNicholas. [Also, see Ryland and Bernard (1983).]

"Most feral populations revert to a form that has the pattern of the wild Western polecat but in a rather dilute, faded form." - Corbett and Ovenden (1980).

Hybrids between ferrets and polecats in the wild in Europe are “the result either of escaped albino ferrets breeding with wild polecats, or are escaped dark or parti-coloured animals which man has produced deliberately by crossing the domestic albino ferret with the wild polecat.” - Lever (1985).

Domestic ferrets have long been hybridized with European polecats in order to develop certain desirable traits, such as improve pelt characteristics (Hagedoorn, 1954). Poole (1972) conducted experiments comparing certain developmental and behavioral characteristics, such as alertness and fear of man, among captive ferrets, polecats, and ferret-polecat hybrids.

Mustelid Skull

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BIOLOGY, PHYSIOLOGY, AND DISEASES

Behavior

Natural history of feral ferrets in New Zealand:

Ferret, by B. K. Clapperton in Advances in New Zealand mammalogy 1990-2000, Journal of The Royal Society of New Zealand, 2001.

In describing ferrets, Corbett and Ovenden (1980) wrote, "Feral animals behave as polecats."

Unlike prairie dogs or ground squirrels, which live in colonies, ferrets are fairly solitary and individually require a sizable home range. According to a study by Moors and Lavers (New Zealand J. of Zool., 8: 413-423), "the males and females share the same ground but exclude other ferrets of the same sex, at least from the centers of their home ranges. A ferret may shift its home range during its life according to the distribution of food and neighbors. In New Zealand in a [wetland]/dune/farmland area home ranges of males averaged approximately 100 acres and that of females, approximately 30 acres."

For other references on behavior, link to the bibliography index.

Diet

Ferrets in the wild feed on a wide array of small ground-dwelling animals. The best information on diet of feral ferrets comes from studies in New Zealand. [Link to dietary studies in New Zealand]

Ferret predation was studied in pastoral habitats in southern New Zealand; ferrets preyed upon a variety of mammals, birds, reptiles, and invertebrates, but lagomorphs constituted 77% of the diet, and "All indications from this and previous diet studies in New Zealand is that ferrets are opportunistic, generalist predators." - Smith, et al. (1995)

For other references on diet, link to bibliography index.

Predatory Behavior

"The predatory behavior of the ferret (Mustela putorius f. furo L.): In young male ferrets the killing of prey can be observed first between day 55 and 60 of life. Up to day 70 in only 40% of all prey-catching experiments the prey is actually killed. From day 83 on all ferrets succeed in killing their prey (mice). The killing time is on the average 77 s(econds). On the other hand, ferrets reared in isolation from day 30 do not kill their prey reliably before day 90. The killng (sic) time is essentially the same as in normally reared ferrets."  - Kastner, D., and R. Apfelbach (1981)

Development of prey-catching behavior

"To hunt, drive and kill is a ferret’s natural instinct and disposition." - Harding (1915)

Ferrets that are used in hunting rabbits typically chase the prey out of burrows, but the ferrets occasionally kill their prey underground:

Links:

Growth, Development, and Life Span

Ferrets may be considered to be adults at about 6 to 7 months of age, when they have attained nearly full adult size. In the wild in semi-arid N ew Zealand, ferret mortality is naturally high.

Ferrets in captivity rarely exceed 10 years of age.  In the U.S., average life span is typically described in veterinary sources as 5-8 years. In contrast, some U.S. pet ferret literature sources suggest longer lifespans, typically up to 10 or 11 years.

Dick Nutt, in Once Upon a Time in America (1998), wrote, "On the veterinary side of life there are some areas where British vets will disagree with their American counterparts, and when Mike Oxenham, probably the top ferret vet in Great Britain, gave lectures in the States he caused some surprise when he compared the average life-spans of home bred ferrets in this country to the much shorter average of mass bred ferrets for the pet trade in USA."

Pathology links:

Public Health links:

Link to California public health issues.

Habitat

Ferrets in the wild occur chiefly in temperate woodlands, grasslands, pastoral habitats, wetlands, and other areas similar to the habitats used by European polecats. The best information on feral ferret habitat use comes from studies in New Zealand. Link to habitat of ferrets in New Zealand.

According to Jeffares (1986), "Because of its very simple digestive traits, the feral ferret must have available a permanent source of water."

HISTORY OF FERRETS IN THE U.S.

"On ce Upon a Time in America" - Dick Nutt, National Ferret Welfare Society, U.K.  

1862 Pennsylvania law prohibiting use of ferrets to hunt rabbits in three counties

Other history sources:

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USES OF THE DOMESTIC FERRET

Hunting | Lab | Fur | Pet | Breeding

Ferrets Used in Hunting Game and Rodents

Domestic ferrets were used as an aid in hunting rabbits in the Middle Ages in Europe ("B ook of the Hunt"). In England, a 1390 law restricted ownership of ferrets to prevent rabbit poaching. Ferreting is used in the U.K. and other countries today, mainly for rabbit hunting and control. As a means of controlling local rabbit populations, it is an alternative to gassing, snaring, shooting, and releasing pathogens.

Ferrets have been used in killing rodents, as well.  “If a ferret has been well handled and is of proper age, very little training is necessary to make fine ratters of them.” - Harding (1915)

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Ferreting articles

Use in falconry (U.K.)

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Instances of Ferrets Being Illegally Used as Hunting Animals in California

In February 1973, California Department of Food and Agriculture reported that a white ferret was found in possession of two falconers who had been stopped by a State Park Ranger at O'Neill Reservoir, Merced County. The ferret was confiscated by Department of Fish and Wildlife.

A recent poaching case "resulted in the conviction of a suspect who possessed several ferrets at his residence and was using them to hunt rabbits. He was fined $370 in Tulare County and $1,215 in Kings County, totaling $1,515, one day in jail, and three years probation." - Calif. Dep. Fish & Game, Region 4 News, February 1996.

Use of domestic ferrets for hunting in states of the U.S. (see 1996-97 Nationwide Survey)

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Ferrets as Laboratory Animals

"While the ferret was recognized in the early 20th century as having useful applications for medicine, it has only been since the late 1960's that this animal has become an important animal model for medical research." - Partners in Research

Wellstead (1981) wrote that in Britain, “The number of working animals now runs second to those kept as laboratory animals.” Compared with other species, the number of ferrets now used in research is relatively small, but laboratory ferrets have many research uses, including toxicology studies and bacteriological and virological studies. Ferrets are particularly important in research on influenza, because ferrets are infected by human type A and B influenza viruses, which can be transmitted between humans to ferrets and from ferrets to humans.

Importation and possession of domestic ferrets for medical research and for educational purposes are legal in California, under permit from the Department of Fish and Game, as authorized by the Fish and Game Commission. Fewer than 1,000 ferrets are possessed under California permits, mainly for use at university and medical research facilities.

Ferrets as Fur Animals

Domestic ferrets have been raised in captivity in the 20th century as fur animals, as minks have been. The fur or pelt is called "fitch." Also, the term "fitch" may be used to describe a ferret that is being raised for its fur, to a color pattern similar to that of European polecats, to hybrids of ferrets and polecats, or to European polecats themselves.

Fitch fur is used in the manufacturing of garments and other items, including fishing flies.         

"Specially-bred ferrets, called fitches, have been farmed in New Zealand for their fur." (New Zealand Ministry of Agriculture and Fisheries). Jeffares (1986) evaluated the prospects for trapping feral ferrets in New Zealand for use in the “fitch” fur market.

According to the International Fur Trade Federation and the Fur Commission USA, mink and fox are the main fur farm animals produced in the world, and other "species farmed on a smaller scale include nutria, chinchilla, fitch, sable and finn raccoon."

Ferrets as Pets

Pet ferrets and hunting ferrets are the same animal. Only recently have ferrets been widely used as pets (Wellstead 1981). Promotion of ferrets as household pets began in the 1970s in the U.S. California Agriculture border stations intercepted illegally imported ferrets beginning in 1976/1977, when there were 3 detections (of one or more ferrets each), but the number of detections of vehicles with ferrets steadily increased annually thereafter, growing to 150-300 detections per year by the mid 1980s.

Nationwide pet ownership surveys conducted for the American Veterinary Medical Association and the pet food industry do not support claims made by many ferret organizations that there are many millions of pet ferrets in the United States. A California Department of Fish and Game review of such pet ownership surveys showed that the ferret has not become the "third most popular" pet mammal in the U.S., as is often claimed. The population of pet ferrets is one and one-half percent of the nation's pet cat population. [Full report | Tab le 1, numbers of ferrets and other pets in U.S. | Table 2 , percent of U.S. households with small mammal pets]

In many municipalities in North America, ferrets are not legal to own ("Ferret- Free Zones"), even if the state does not prohibit ownership. Also, ferrets are illegal to have as pets in Queensland, Australia. In March 2002, the government of New Zealand announced that keeping of ferrets as pets or for fur farming would be banned (Ferret Breeding and Sales Banned).

"Keeping ferrets is no easy task and requires dedication. Only people who are prepared to give time and effort should consider having them as pets."  "Some members of the Society offer a 'rescue service' to collect ferrets that have been abandoned, lost or just found wandering in search of food. One of the disheartening aspects of this is that we are often called upon to collect unwanted pets. It seems that the novelty of keeping an 'exotic' soons (sic) wears off." - In formation for Owners or Would be Owners of Ferrets (U.K.)  

"Over the past decade or so, ferret shelters and rescues started popping up in every state in the country. The devoted directors of these shelters have realized that there are many, many ferrets that are unwanted and either abandoned or left living in homes that don't really want them. Ferrets were considered a "fad" pet, especially in the 1980's, and many people rushed out, dropped $100-$200 for this "cool" pet, then the novelty wore off. Some people simply lost interest; others didn't realize the committment (sic) needed for a ferret. Whatever the reason, ferrets were in need of rescuing." - Pennsylva nia Ferret Rescue Association.

Domestic ferret as pets in states of the U.S. (see 1996-97 Nationwide Survey)

Other links on ferret pet keeping:


Ferret Breeding in the U.S.

Ferrets are bred for fur, laboratory animals, and pets.  Some small-scale breeders produce "home-raised" ferrets for sale as pets, although owners of pet ferrets are often warned about the difficulties inherent in attempting to breed their ferrets. Besides, most pet ferrets have already been sterilized before sale. Many are sterilized by 4 to 8 months of age, and some commercial breeders sterilize them much earlier--by 6 weeks of age, or less.

Most ferrets in the nation come from small and large-scale ferret breeders or farms. Marshall Farms in New York is the leading supplier in the U.S. of laboratory ferrets and pet ferrets.

Breeding of domestic ferrets in states of the U.S. (see 1996-97 Nationwide Survey)

Hunting Skills of Pet Ferrets

Pet Ferrets Kill Pests

Pet Ferrets Kill Household Pets

  • According to Jeans (1994), ferrets will usually kill small bird and mammal pets.
  • "Pets that are usually not a good idea to have around ferrets are; birds, snakes, gerbils, hamsters, mice and rats. Ferrets are mousers by nature, and will attack and sometimes kill small rodents and birds. Snakes will see ferrets as prey, and the ferret does not usually come out the winner."

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Other Carnivore Species Used as Pets

Cats and dogs, the most popular pets in the U.S., are carnivores, but most of the other popular mammal pets are rabbits or rodents (e.g., mice, rats, hamsters, guinea pigs). Domestic ferrets are carnivores, also. North American exotic pet breeders and promoters offer a long list of "hand-raised" wild carnivores as pets. Examples include wild cats (such as serval, caracal, Siberian lynx, Canadian lynx, bobcat, fishing cat, cougar), wild members of the dog family (fennec fox, bat-eared fox, black-backed jackal, raccoon dog), viverrids (civets and genets), mustelids (zorilla and otters) and raccoons and their relatives (coatimundi and kinkajou). All of these are restricted species in California and are not legal to possess as pets. The European polecat, which is the same species as the ferret, is also illegal to import or possess as a pet in California. The polecat, which "can become extremely tame" (Wellstead, 1981, pp. 14-15), is not usually a good candidate for pet keeping, but it is used by breeders to cross with ferrets to develop hybrids with certain traits.

Breeders offer an assortment of hybrid exotic cats, such as the "bengal", resulting from crossing domestic cats with wild cat species. Such hybrids, or purported domestic cat-wild cat hybrids, are not restricted in California and are treated as domestic cats. 

There are advocates for keeping domestic minks and pen-raised "domestic" skunks as pets:

American Mink as a Domestic Pet

Promotion of ranch mink as pets stems from the breeding of mink for fur:

Striped Skunk as a Domestic Pet

Striped skunks are promoted and available nationally as pets, although possession of pet skunks is illegal in California and in many other states. The campaign for promotion of skunks as pets is similar to that for ferrets in many respects. Skunks are produced on fur farms for the pet trade, and these captive-bred skunks are referred to as "domestic" skunks. Pet skunk groups have been formed; skunk breeders produce coats of a variety of colors and stripes; and in the U.S. there are skunk shows, similar to dog and cat shows. Advocates for the keeping of skunks as pets are attempting to gain approval of a rabies vaccine and quarantine period.

Because of the prevalence of rabies in skunks in California, Department of Health Services regulations prohibit capturing, holding, or importing skunks for pet-keeping purposes (California Code of Regulations, Title 17, Section 2606.8).