Fisher (animal)

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Fisher

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Martes
Species: M. pennanti
Binomial name
Martes pennanti
(Erxleben, 1777)

The fisher is a North American marten, a medium sized mustelid. The fisher is agile in trees and has a slender body that allows it to pursue prey into hollow trees or burrows in the ground. Despite its name, this animal seldom eats fish; the name may originate from the French word fichet, which referred to the pelt of a European polecat. In some regions the fisher is known as a pekan which is derived from its name in the Abenaki language.

Contents

[edit] Description

Adults weigh between 2 and 7 kg (4-15 lbs) and are between 65 and 125 cm (29-47 inches) in length. Males are about twice the size of females, with the smallest females having been recorded being as small as 1.4 kg (3.1 lbs), hardly larger than most other martens, and males at as much as 9 kg (20 lbs). Their coats are darkish brown, with a black tail and legs; some individuals have a cream-colored patch on the chest. All four feet have five toes with retractable claws. Because they can rotate their hind paws 180 degrees, they can grasp limbs and climb down trees head first. A circular patch of hair on the central pad of their hind paws marks plantar glands that give off a distinctive odor, which is believed to be used for communication during reproduction. Fishers are also known for one of their calls, which is often said to sound like a child screaming, and can be mistaken for someone in dire need of help.

[edit] Hunting and diet

Fishers are solitary hunters. Their primary prey include hares, rabbits, squirrels, mice, shrews, and porcupines. Their diet may also contain small birds, fruit and berries, as well as deer in the form of carrion. While fishers and mountain lions are the only regular predators of porcupines, the fisher is the only predator to have a specialized killing technique. As observed by Robert G. Snyder in the Adirondack mountains of New York, a fisher first approaches from the direction the porcupine is facing. The porcupine tries to protect itself by turning to present its tail, covered with quills, to the attacker. The fisher then jumps directly over its prey, forcing the porcupine to keep turning to protect its vulnerable head. A dozen or more such maneuvers suffice to exhaust and confuse the porcupine into a stupor in which it can no longer protect itself. Then, by repeatedly biting and scratching at the porcupine's face, the fisher causes it to bleed to death. The fisher eats the porcupine by flipping the dead animal over and starting with its unprotected belly.

Fishers are also known to eat ground nesting birds such as grouse and turkeys. Often, young of the year and eggs make easy targets. Also, in some areas fishers can become pests to farmers because they will get into a pen and kill large numbers of chickens. Fishers have also been known to eat small pets left outside, such as stray cats and dogs. While this is rare, when densities are high and food resources are low, animals may become desperate.

In 2005 a Boston Globe article told of fishers attacking cats.[1] A July 4, 2007 article in the New York Times raises the possibility that fishers have turned up in Hopewell Township, New Jersey, causing concern among cat owners. Zoologists are skeptical, suggesting other animals could be responsible, observing that it would be difficult for fishers to migrate into the area.[2] A study done in 1979 examined the stomach contents of all fisher trapped in the state of New Hampshire. Cat hairs were found in only one of over 1,000 stomachs.[3] Attacks on domestic cats may be documented, but zoologists suggest a bobcat, coyote, or dog is more likely to kill domestic cats and chickens.

[edit] Reproduction

Female fishers first breed at one year of age. The fisher breeding season spans late February through late April. There is a ten-month delay after breeding before implantation of the blastocyst phase of the embryo occurs, resulting in a one-year gestation period. Litters are produced annually. The young are born in dens high up in hollow trees.

Kits nurse for about 4 months and begin to eat meat before they are weaned. The kits' cries mimic that of baby kittens.

[edit] Distribution

Fishers are solitary. They do not congregate and only associate with other fishers for mating purposes. Historically, fishers have tended to hide deep in wooded areas and completely avoid open spaces. Recent studies, as well as anecdotal evidence, suggest that the highly adaptable fishers have begun making inroads into suburban backyards, farmland, and even semi-urban areas.[4]

The fisher is found from the Sierra Nevada in California to the Appalachians in West Virginia and north to New England (where it is often called a fisher cat), as well as in southern Alaska and across most of Canada. Fishers are present in low density in the Rocky Mountains, where most populations are the result of reintroductions. There is recent evidence, however, that a Montana population persisted in a refugium despite extensive fur trapping in the area during the 1800s and 1900s. They have spread from Vermont into southern New Hampshire and north-central Massachusetts, and have recently been reintroduced in Michigan and Pennsylvania. [5] Fishers are most often found in coniferous or mixed forests with high, continuous canopy cover. On 27 January 2008, fishers were reintroduced in the Olympic National Park in Washington State. Fishers, native to Washington, have not been known to exist anywhere in the state for generations, because of overtrapping in the 1800s and early 1900s and the loss of old-growth forests. Fishers have recently been reintroduced in Montana, Oregon, and in total, about 35 other fisher transfers have been done across the country [1].

[edit] Conservation status

Fisher populations have declined because of loss of forest habitat and because of the tolit act. Their brown, soft fur is sought after by the fur trade and pelts can fetch high prices, keeping the demand for fisher pelts on the rise. Fisher have the reputation of being shy and secretive, and they are difficult to breed in zoos. However, on March 23, 2008, three fisher kittens were born at the Minnesota Zoo in Apple Valley, Minnesota [2].

Fishers, along with most of New England's other furbearers, were nearly exterminated from New England because unregulated trapping since the mid-1600s had taken its toll. The forested habitat preferred by the fisher was at a premium in those days, because much of New England's land was in agricultural use. Some measure of protection was afforded the fisher in the early 1900s, but it was not until 1934 that total protection was finally given to the few residual fisher left in the North Country.

The fisher was again abundant enough in 1962 to declare an open season. During the early 1970s the value of fisher pelts soared, leading to another population crash in 1976. After a couple of years of closed seasons, fisher trapping re-opened in 1979 with a shortened season and restricted bag limits. The population has steadily increased since then, with trappers taking about a thousand fishers a year in the late 1990s, despite a much lower pelt value.

Fishers were reintroduced into several states including Pennsylvania, Connecticut and West Virginia after being nearly wiped out by trapping and habitat destruction in much of North America, sometimes in an effort to control porcupine populations.

[edit] References

  1. ^ On the wild side: Once nearly extinct, weasel-like fishers thrive in the suburbs, where their ravenous feeding habits threaten family pets. Keith O'Brian, Boston Globe, 25 August 2005
  2. ^ A Cat Fight? Sort of, Only Louder and Uglier Kareem Fahim, New York Times, 4 July 2007
  3. ^ The Fisher: New Hampshire's Rodney Dangerfield
  4. ^ A Fierce Predator Makes a Home in the Suburbs Katie Zezima, New York Times, 10 June 2008]
  5. ^ A Fierce Predator Makes a Home in the Suburbs Katie Zezima, New York Times, 10 June 2008

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