Fisher

A Fisher animal also commonly known as a fisher cat, black fox, black cat or pekan is a mammal that is biologically referred to as Penakia pennanti that belongs to the family of Mustelidae and is indicated as fisher Mustelid. The subfamily they belong to is known as Guloninae with order Carnivora. They are the small mammals that are native to North America and prefer to dwell in the northern forests like taiga and are predominantly carnivorous creatures. They are often trapped by the humans for their blackish-brown fur that is considered to be most valuable, especially the one that the female of the fisher family possesses. They are very closely related to the American marten but is larger in size as compared to the marten. As they are trapped by humans for their fur, the humans do far have been their biggest predator.

The pelts were so high in demand from the 18th century that they were almost on verge of local extinction in many parts of the United States at the beginning of the 20th century. Many animal protection and conservation measures have helped the species to revive but as compared to their existential numbers they are very few in recent times. During the 1920s when the pelt price started to rise high many locals of Northern America started breeding fishers but due to their delay in reproduction, it made the breeding of the animal very difficult. Later on, as the price of the pelt started to drop, the breeding of the fishers by locals also started dropping at an alarming rate. Usually, fishers avoid coming in contact with humans directly or indirectly but the intrusion of humans into the forest marks a danger to their territory as well. A well-illustrated picture of the fisher cat is provided below as the entire article deals with the necessary pieces of information about fishers. 

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Taxonomy and Evolution of Fisher Cat

The name Pennanti which is a name of Latin origin was first given to the fishers to honour a biologist named Thomas Pennant who first described “what is a fisher cat” and its characteristics in the year 1771. In 1765 the characteristics and other details about the creature were described by Buffon in the year 1765 and called it a Peckan. There have been many other biologists in the 18th century who have done their studies individually unaware of each others’ findings have given separate names to the same specimen like Mustela Canadensis and Mustela Melanorhynca. Much later in 1843, the fisher was finally classified as a mammal of genus Martes by Smith. This was then followed by a lot of DNA and advanced DNA analysis that determined that both the fisher and genus Martes are the descenders of a common ancestor but the fisher was quite distinctive of its features to be removed from the previous genus and was given its own genus that was reclassified as Pennanti. These specimen can be distinguished by their arrangement of teeth where they possess four premolar teeth on both lower and upper jaws. A similar species to fisher, Mustela only have three of the teeth in the upper and the lower jaw. The fisher in total possesses 38 teeth. Their teeth and skull structure is illustrated in the diagram below. 

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Evolution 

Many of the studies indicate that fishers were the primitive ancestors of North America from the era Pliocene that is extended between 2.5 to 5 million years ago. Now the fossil study of the two distinct species named Pekania Palaeosinensis and P. anderssoni of the mustelid family was initially found in Asia that is further south. But the fisher named P. Diluviana that was considered as an original fisher with the same characteristics as today’s specimen was found in North America during the middle Pliocene era. But the strong resemblance between P. Diluviana to the Asian specimen during the study of the fossils also indicates the probability of migration of P.prnnanti from Asia to North America happened that was first discovered to be a species of the Late Pleistocene era that is about 125.000 years ago. The characteristics of the ancient Pleistocene Fischer is much similar to that of the modern fishers of today but the study suggested that it was not localised to North America but have its origin extended to further South than it is today. In the year 1935, Goldman has been able to identify three species that were named Martes. Pennanti. Columbiana, M.P. Pacifica and M.P. pennanti but there was a big debate regarding the existence of the species that are mentioned. Finally, in the year 1959, it was concluded that these species cannot be treated as separate individual species because of their extensive resemblance to the fur structure and pattern and the skull characteristics by a biologist named E.M. Hagmeier. Even today fishers are treated to be a monotype species that do not have any extended subspecies. 

Biology and Behaviour of Fisher

Physical and Biological characteristics

The wild fisher cat is generally a middle-sized mammal as compared to the size of a domestic cat. Their body structure is lower without much ground clearance with long and thin shapes. though the physical features of both the genders are the same the mammal is dimorphic sexually, that is the dimension of the male body is much larger as compared to its female counterparts. The length of a male ranges from 90 to 120m cms and weighs varies from 3.5 to 6.0 kgs. The female counterpart, on the other hand, has a length ranging from 75 to 95 cms and the weight is in the range of 2 to 2.5 kgs. But the tail length in both male and female fishers is measured around 33 to 42 cms. Though the largest wild fisher cat known so far had a bodyweight of 9kgs. 

The fur of the fishers changes with the season and is different in texture in males and females. The male fur is more rough and harsh in texture as compared to its female counterpart. The texture of the coat of fur is dense and glossy in early winters with 30mm dense fur on the chest and 70mm dense on the back of the body.  The colour of the fur ranges from deep brown to black as it appears darker in shade in contrast to the snow. The fur on their face and shoulder appears to be gold or silver due to the tricolour of the guard hair. The under area of the fisher is completely brown in colour and sometimes it has either some white or cream colour fur that gives an illusion of patches underneath. The fur colour lightens up during summer and it undergoes moulting as well that starts in late summer and finish somewhere between November and December. 

The fishers usually have five toes in a foot with claws that are retractable and is uncovered and unprotected. They have large feet with four paddings on each foot with some rough hair that grows between the pads and the toe of the hind leg that provides them more grip while climbing up the slippery snowy surfaces during winters. The fishers are the few among mammals that have the ability to climb down the tree at head down position because of their very flexible ankles of the toe. Especially the hind leg toe ankle that can rotate to 180 degrees that support them in manoeuvring climbing and getting down a tree with head first. The patch of hair present on the central padded of the paws of the hind legs marks planter glands that result in distinctive odour. And as the patches become larger during the breeding the mark of paws left behind the smell by which the fishers find one another to initiate mating.  

Hunting and Diet 

The fishers are generally aggressive predators that primarily feeds on porcupine and snowshoe hares. The hunting pattern of the fisher while hunting down a porcupine is noted and it was seen that it tends to bite attack the porcupine face multiple times and it takes about 20 to 30 minutes to execute it completely. They also sometimes feed on small birds, insects, nuts, berries as well as mushrooms as their supplement diet. As they are most active during the dawn and the night time they are termed as crepuscular. They are active almost throughout the year and are solidarity mammals who come to each other only for mating. Thus due to the solidarity hunting pattern as well, their prey depends on the individual size of the fishers. They are also known for preying on big animals like wild turkeys, bobcats and Canada lax. Though most of the time the cats predominate the hunting process and is one of their main predators but sometimes they become the prey for the latter. The fisher cat’s hunting range vary from summer to winter. In summers their hunting range is about 6.6 Km2 whereas in winters the hunting range is extended to 14 Km2. sometimes depending on the temperature and the habitat condition the hunting range may stretch to 20 Km2 in winters. Because of the overlapping territory of the male and female fisher, the male behaviour is dormant over females due to its size and their desire to increase mating success.

Reproduction 

The breeding cycle of the female fisher starts at one year of age and continues throughout the whole year-round. The mating takes place between late March and early April. But then the blastocyst implantation gets delayed for almost a year till the mid of February of the following year. The gestation period for the female fisher is about 50 days when it gives birth to babies that vary from one to four at a time. The oestrus period for the female starts after 7 to 10 days of giving birth. While the gestation period is on for the females they find hollow trees for shelter where they give birth to the kits that are born blind, helpless with very fine hair on their bodies. After about three weeks they began to crawl and in the seventh week, they first open their eyes. In the eighth week, they start to climb trees after which they switch to solid food for the first time. The kits actually become intolerant of their mates at four months and in about five months the mother fisher pushes the kits away on their own and soon the juvenile fishers create their own range.  

Fisher Cat Habitat

Though they are very good climbers they mostly prefer to stay on the ground. They mostly habitat in extensive dense forests like that of typical boreal forests. They enjoy living in a continuous forest area. But they also choose to stay in mixed hardwood areas as well as in conifer forests. They mostly prefer the forest area that has almost 80% of the coverage area in density rather than the forest with 50% coverage density. They are commonly found in forests that are old grown. As the female fisher during their gestation period needs to den in the hollows of trees that have larger space, thus heavily logged forests with extensive second growth is not preferred by the female fisher. As the fisher mostly lives in the coarse woody debris in large amounts on forest floor thus it mostly prefers an interface area between the forest and river called riparian. They generally avoid the forests where forest fire occurs at regular intervals burning down the forest debris.  

Distribution of Fisher Cat

They are found largely in the northern dense forests of North America. The forests that are preferred by the fishers are mostly mixed deciduous-coniferous forests as well as boreal that run across Canada. The forest land extends from Nova Scotia in the east to the Pacific shore of British Columbia and further north to Alaska. They are also seldomly found in far north as Great Slave Lake in Northwest territories and even in far south in the mountains of Oregon. Few of their population are also widespread in the Sierra Nevada in California, densely in New England, in Appalachian mountains of Pennsylvania, Maryland, West Virginia and Virginia. In the 19th and the 20th century, almost all the population of fishers were removed from the southern to the eastern parts of America that include Most American states, Nova Scotia as well as Canada. Later in the 1930s, the trapping of this specimen was completely banned. There were also many measures taken to regrow the forests in abandoned farmlands with the introduction of proper forest management. This has immensely helped the fisher to find a new habitat for them and recover their lost population density. The scattered fisher population is seen in the Pacific Northwest in recent times. From the year 2008 to 2011, as close as 40 fishers were reintroduced near Stirling city of Sierra Nevada. The new fisher population is also been taken to the Yosemite National Park that is situated along the northern boundary of California between the Pacific Coast Range and Klamath Mountain. 

Fishers are predominantly carnivorous animals of smaller size and with dense coarse fur in their body. They are the Native of North America. They mostly dwell in the deciduous and coniferous forest as they prefer continuous dense forests for their habitation. They are generally the specimen found in the Southern part of the world but a similar species fossil was also found in Asia a few million years ago that had a striking resemblance and characteristics of the fisher. They are also known as wild fisher, fisher cat, black cat or black fox. They have evolved with their very specific characteristics and thus have been given their own genus and does not relate to any subfamily.