The Ferret Hotel

   

The polecat (Mustela putorius) is of considerable conservation significance in Britain. This is particularly so because of its current recolonisation of many areas of lowland Britain from which it was trapped to extinction at the end of the 19th century.

         
 

Facts

Kingdom	Animalia
Phylum	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Mustelidae
Genus:	Mustela
Size:	Tail length: 11 - 15 cm Head-body length: 31 - 41 cm (male)
Weight:	Female: 0.8 kg Male: 1 kg

 

Status

Classified as Extinct in the Wild (EW) by the IUCN Red List 2004, and listed on Appendix I of CITES .

Description

One of the world's rarest mammals, the black-footed ferret is the only ferret native to North America, and is classified as Extinct in the Wild. This slender animal has a yellowish coloured coat, pale underparts  and a dark tail tip and black feet. The muzzle, throat and forehead are white and there is a black mask around the eyes. As with most members of the genus Mustela, the males are larger and much heavier than females. The legs are short and the large front paws are armed with claws for digging.

Range

At present, free-ranging black-footed ferrets are known only from reintroduction sites in Arizona, South Dakota, Wyoming, Montana, Utah, Colorado, and Chihuahua (Mexico). The species was once common throughout the Great Plains from Alberta in Canada to southwestern USA, but became extinct in the wild in 1987.

Habitat

Inhabits shortgrass and midgrass prairies, where there is an abundance of prairie dog (Cynomys spp.) 'towns'. A very large area of suitable habitat with a large population of prairie dogs is required to support the species; a single black-footed ferret needs between 40 and 60 hectares.

Biology

The black-footed ferret is an alert, agile, nocturnal animal, which spends the day in prairie dog burrows. More than 90% of the diet consists of prairie dogs, which are attacked whilst they sleep in their burrows, although mice, ground squirrels, voles and other small mammals are also taken.

This species is solitary except in the breeding season that runs from March to April, and females rear their offspring without help from the male. Litters can contain between 3 - 6 young (known as kits), which are born blind and helpless and covered with thin white hair. The kits stay in the burrow for about 42 days before venturing above ground, and remain with their mother until the autumn, after which time they disperse. These ferrets have excellent senses of hearing, sight and smell, and olfactory communication (urination and defecation) is very important in the maintenance of dominance hierarchies and following trails at night. Vocalisations include chattering and hissing.

Threats

The number of black-footed ferrets plummeted in the first half of the 20th Century, primarily as a result of habitat loss. Prairies have been modified for intensive agriculture and there is now less than 2% of the original ferret habitat left. The ferret's main prey, prairie dogs, were systematically poisoned in vast tracts of their habitat by a government eradication programme in the mid 1900s. Prairie dog burrows were thought to damage cropland and ferret numbers fell in direct proportion with the dramatic decline of their prey. The final threat to black-footed ferret numbers, and perhaps the most pertinent today, is disease, particularly canine distemper and plague. Plague, introduced to North America, causes even greater devastation in populations of prairie dogs and ferrets than it caused in human populations of Europe and Asia .

Conservation

Wyoming in 1981. Under initial protection measures, this population increased in numbers but then became infected by canine distemper and plague, which threatened to completely wipe out the species. As a last resort the final 18 wild animals were caught and brought into captivity between 1985 and 1987, and a successful captive-breeding programme has been running ever since. The U.S. Fish and Wildlife Service's revised 'Black-Footed Ferret Recovery Plan' of 1988 prescribed the long-term target of establishing 10 or more separate, self-sustaining wild populations; aiming to have 1500 ferrets in the wild by 2010. The key to the long-term viability of this species is sufficient prairie dog habitat, but the situation is hopeful at present, as new populations have now been established in Wyoming, South Dakota, Arizona, Colorado, Utah, Montana, and Mexico.

 

                  

The Ferret Family

 

Class: Mammalia

Order: Carnivora

Family: Mustelidae

 

 

 

The Weasel

 

 

 

 

The weasel is found throughout Britain, however they are absent from Ireland and other islands off shore. Weasels will live in any habitat where their small prey is found, for example, urban areas, lowland pasture, woodland, marshes and moors. However, weasels are less common at higher altitudes.

 

The Polecat

 

The largest member of the genus Mustela in Britain, polecats have weasel-like slender bodies, short legs and a broad head. Males are much larger and heavier than females, but other than this size difference they share the same general appearance, with a buff to black coloured coat, and a black face with a white mask around it. During winter the coat is thick, lustrous and glossy, but in summer it is thinner and appears somewhat faded.

 

The Mink

Adult male mink weigh about 1.2kg and are about 60cm from their noses to the tip of their tail. Female mink are smaller. Mink are an opportunist predator, taking a wide range of small mammals, fish, birds and invertebrates. They are territorial, and aggressive towards their own kind, males will not tolerate other males within their range, which has also ensured that they always remain at a low population density.

The Pine Marten

Found mainly in north west Scotland, the Peak District and the Lake District. Also reports of some in Churnet Valley, Staffordshire, they have chestnut brown fur with a creamy-yellow throat and chest. They're equipped with strong claws which they use for climbing trees to catch their prey.

Pine martens almost became extinct in Britain after years of persecution by gamekeepers, and hunters who trapped and killed them for their fur. Thanks to the work of conservation groups they are slowly making a comeback in some areas

The Wolverine

The elusive wolverine has a fearsome reputation - it is the largest member of the weasel family. The remoteness and voracious appetite of these creatures have led to an aggressive reputation. Males are much heavier than females and both have a stocky body and short legs. They are well adapted to the cold habitat of their northern range with a thick, bushy coat and broad, hairy paws. The glossy coat is dark brown with a paler stripe across the rump and along the sides of the body; some individuals have white throat patches. The powerful jaws and large teeth are able to demolish frozen carrion and bone. Wolverines carry their head and tail lower than the arched back and their gait appears somewhat humpy and lumbering although they can move very quickly when necessary.

 

The rarest native mammal in the United States, the black-footed ferret is a short-legged, slender-bodied weasel. It measures just 1 1/2 feet (46 cm) nose to tail. This small carnivore once was widely distributed throughout the North American Great Plains from Alberta, Canada, south through the Rocky Mountains to the southwestern United States. The last wild black-footed ferrets were taken into captivity in 1987. Today, the ferrets have been reintroduced to a few limited areas in the state of Wyoming.

Natural History

The black-footed ferret is a nocturnal prowler whose fate is closely tied to that of the prairie dog. The ferret eats ground squirrels, mice, birds, and insects. It lives in burrows dug by prairie dogs, which also are its primary prey. A colony of prairie dogs 100 to 148 acres in size is necessary to support one ferret.

Causes of Endangerment

Killing of Prey and Habitat Loss

Massive hunting and poisoning campaigns against the prairie dog, its main food source, caused the ferret to decline. Since the pioneers arrived on the Great Plains, ranchers and farmers have conducted an extensive campaign to get rid of prairie dogs, which were considered pests. Discovery of sylvatic plague in the colonies stepped up efforts to eliminate the prairie dogs. From 1900 to present, prairie dog populations plummeted to about 5 to 10 percent of their former numbers.

The wholesale conversion of prairie to crop land further impacted the ferrets and their prey. Just one percent of the United States' native prairie remains today (see Spotlight on The Prairie). With patches of prairie becoming fewer and farther between, ferret habitat became increasingly fragmented. The remaining black-footed ferrets became more isolated, and unable to reproduce. Crowding wildlife into smaller islands of habitat causes inbreeding. The lowered immune responses of inbred animals increases the likelihood of epidemic disease. In 1984, an outbreak of canine distemper brought by domestic dogs and coyotes devastated the already-precarious ferret population. By 1985, there were just 10 known black-footed ferrets in the wild.

Conservation Actions

Protection Under the Law

The black-footed ferret was first officially recognized by the United States government as threatened in 1967 and was listed as endangered when the Endangered Species Act (ESA) was created in 1973. By the time the United States Fish and Wildlife Service adopted a recovery plan for habitat protection in 1978, however, the ferret had declined to near extinction. The recovery plan has since been modified with emphasis on captive breeding and reintroduction.

Captive Breeding and Reintroduction

The Wyoming Department of Game and Fish coordinates the Species Survival Plan (SSP) for black-footed ferrets. Captive breeding populations are maintained at the Sybille Wildlife Research Station in Wyoming and several zoos.

After the black-footed ferret population was decimated by disease, biologists determined that the remaining wild ferrets were not a viable breeding population. The last 12 ferrets were captured and combined with 6 ferrets already in captivity to bring the world total to 18 ferrets, all in captivity, in 1987.

Captive breeding has been successful. Sufficient numbers of prairie dogs were born to allow reintroduction to be attempted after just a few years. In 1991, the first reintroduction of 49 juvenile ferrets was completed. Careful monitoring showed that 12 percent of these ferrets were able to survive the winter. The discovery of two wild-born litters was a particularly good sign. A second group of 90 captive-bred ferrets was released in 1992. Follow-up indicates that survival may be about 25 percent. The majority of ferrets are lost to predation by coyotes. The objective of the recovery effort is to establish ten geographically distinct free-ranging populations totalling 1,500 ferrets by the year 2010.

Obviously, black-footed ferret reintroduction will be successful only if there are sufficient numbers of prairie dogs to support the ferrets. Efforts are being made to preserve habitat and reduce other pressures on prairie dogs. This is a prime example where saving one species means saving a whole ecosystem: the praire dog colonies are a complex natural system supporting many other species besides the black-footed ferret, including birds, mammals, reptiles, insects, and even plants.

Questions for Thought

Captive breeding saved the black-footed ferret from extinction. Other endangered animals have not been successfully bred in captivity. All of the black-footed ferrets alive today descended from just 18 individuals. Some species that are extinct in the wild still survive in captivity, but are unlikely to ever be reintroduced to the wild.