Fisher

(Pekania pennanti)

Fisher in summer coat by Emily Brouwer
Alternate winter coat: Link 1, Link 2

The fisher, also known as the pekan, or erroneously called a fisher cat, is a forest-dwelling mustelid native to North America. The latter vernacular name for the fisher is incredibly misleading, given they do not hunt fish and have no relation to cats.(1) The origin of the common name “fisher” is not known for certain, but it is likely related to the word “fitch”, referring to the more familiar European polecat or pelt thereof. The name derives from the colonial Dutch equivalent “fisse” or “visse”. Early Dutch settlers may have associated the fisher’s appearance with the dark phase of the European polecat.(2) The “cat” half of their common name is likely a superficial comparison to felines.

The fisher was previously placed with the martens in the genus Martes, until DNA analyses suggested the fisher was distinct enough to be place in its own genus, Pekania.(3)

Appearance

The fisher’s dorsal surface ranges from medium to dark brown—changing with the season and being slightly different between sexes, with males having coarser fur than females. In early winter, the fisher’s coat is dense, glossy, and dark brown to black. From the face to the shoulders, fur can be hoary-gold or silver due to tricolored guard hairs. The underside is almost completely brown, save for a cream-coloured chest patch varying in size and shape. During summer the fisher’s dorsal surface tends to be lighter.(2)

Habitat

Fishers tend to be found in coniferous forests, as well as mixed and deciduous forests. They prefer habitats with high canopy closure, as well as habitats with many hollow trees for dens. Spruce, fir, white cedar, as well as some hardwoods are usually found in their habitat.(4) Fishers are more likely to be found in old-growth forests, since trees in heavily logged areas with extensive second growth are not large enough to suit the denning requirements of female fishers.(5)

Behaviour

Fishers are most active at dawn and night. They are believed to be solitary animals that only associate when mating. Although fishers are arboreal like martens, they tend to spend most of their time on the forest floor and prefer coniferous forests, but they are also found in mixed and deciduous forests. They are likely to be found in areas with many hollow trees and continuous overhead cover, with greater than 80% coverage; avoiding areas with less than 50% coverage.(5)

Reproduction

Female fishers are sexually mature after one year of age, with breeding season lasting from late March to early April. After fertilization, blastocyst implantation is then delayed for ten months until mid-February of the following year. After gestating for about 36 days, the female gives birth of one to four kits.(6) Females then enter estrus seven to ten days later before the breeding cycle resumes.(7)

The kits are born blind and helpless, but begin to crawl after three weeks. They open their eyes about seven weeks later,(8) and start to climb after eight weeks. They will depend on their mother’s milk for the first eight to ten weeks of their lives, before being introduced to solid foods. After five months the mother will lead them out on their own, and after a year the juveniles will have established their own range.(7)

Diet

Despite their name, fishers seldom hunt fish. They mainly feed on small mammals, birds, insects, nuts, berries and carrion.(4) In some areas, fishers will occasionally raid chicken coops. Perhaps the most well known trait of the fisher is that they are one of few predators to hunt porcupines. Observational studies show that fishers make repeated biting attacks on the face of a porcupine and kill it after about 25–30 minutes.(5) This is in contrast to the dramatised rumor found in popular literature, where the fisher is said to flip a porcupine onto its back and “scoop out its belly like a ripe melon”.

Predators

Although adult fishers are generally safe from predation, young fishers will occasionally fall prey to hawks, red foxes, lynx and bobcats.(9)

Fur trade

Since the 18th century, fishers have been popular with trappers due to the value of their fur. During the early 20th century, fishers were nearly exterminated due to a combination of overtrapping and changes to their habitat; especially in the northeastern United States. It was not until 1934 when the fisher started to receive some form of protection. A few years of closed seasons helped the fisher make a gradual recovery of their former range, but once their numbers had improved, trapping resumed in the United States in the mid 1960s. Their numbers once again declined in the late 1970s, leading to a few more years of closed seasons. Trapping of fishers again resumed in 1979, but with restricted bag limits. Since then, their numbers have steadily increased.(3)(10)

Direct and indirect poisoning

In 2012, a study conducted by the Integral Ecology Research Center, UC Davis, U.S. Forest Service, and the Hoopa tribe showed that isolated populations of the fisher in California (also known as the Pacific fisher) are exposed to and killed by anticoagulant rodenticides associated with illegal marijuana cultivation.(11) Their study revealed that 79% of fishers tested in California were exposed to an average of 1.61 different anticoagulant rodenticides, with four fishers having died due to these toxicants. A follow-up study in 2015 determined that the fisher’s exposure and mortality from these toxicants increased to 85%, with a now exposed average of 1.73 different anticoagulant rodenticides, resulting in 9 more deaths.(12)

In 2017, Days Edge Productions released Forgotten but not Gone: The Pacific Fisher, to bring attention to the Pacific fisher’s struggles, and the controversial 2016 decision by the U.S. Fish and Wildlife to not list the species under the Endangered Species Act.

Despite their declining numbers, the Pacific fisher has yet to receive federal protection under the Endangered Species Act. On the 14th of May 2020, the United States presidential administration denied Endangered Species Act protections to the Pacific fisher from Northern California to the Canadian border. They were however, granted endangered status in the southern Sierra Nevada.(13)

They do not frequently eat domestic cats or attack humans

A common accusation against the fisher is that they frequently prey on domestic cats.(14)(15) However, contrary to this belief, cats are not on the fisher’s main menu, and despite what some people have claimed to have personally seen or caught, individual experiences do not illustrate what is happening on a broader scale. A 1979-1980 study by the Fish and Game examined the stomach contents of fishers trapped in the U.S. state of New Hampshire, and discovered that cat hairs were found in only 1 of over 1,000 stomachs.(16) Another, more recent study in the U.S. state of Pennsylvania revealed similar results.(17) Unfortunately, despite this evidence, the fisher continues to be blamed for missing cats. Wildlife biologist Eric Orff best summarised the issue, writing:

“Do they eat cats? Sure, as do foxes, coyotes, owls and – more likely – a local SUV. It is the nature of a house cat injured on a highway to seek a hiding place to die, but you can bet a ‘fisher cat’ will be blamed for its disappearance.”(18)

Unless a fisher is threatened, cornered, or suffering from rabies, attacks on humans are extremely rare. There have been a few isolated claims of attacks on humans.(19) However, some of these claims were merely speculation, since the animal was not caught to confirm it was a fisher. Considering most people do not know what a fisher is or how to properly identify them (mustelids are often confused for other animals), mistaken identity is possible. Fishers are simply trying to find food and survive, so to lower the chances of fisher attacks, it is recommended to restrict access to garbage, pets, pet foods, and domestic fowl.(4)

They do not scream

There are several videos on YouTube perpetuating the widespread belief that the fisher screams like a banshee in the night. Apart from the questionable fact that we never actually see the animal in these videos, the fisher is a mostly silent animal and rarely gives its location. These sounds are more likely made by the red fox.(20)

They are not a major threat to wild turkey populations

There have been claims by some (mostly turkey hunters) that the fisher is the main cause for the decline of wild turkey populations. This is yet another unsubstantiated belief about the fisher that make them the target of misdirected anger. While it is possible for fishers to prey on turkeys, the act is hardly common enough to be a significant threat to their numbers.(21) In fact, a recent study in the U.S. state of Pennsylvania revealed that out of 91 fisher carcasses from 2002–2014 that had their stomach contents examined, only three had any trace of bird species in their stomachs, and not a single one was a turkey.(17)

According to the National Wild Turkey Federation, among other factors, it is likely production (not predation) that drives turkey populations. High population densities prevent many hens from finding quality nesting, and may decrease the chances of a successful hatch or the ability to raise a brood. A quality habitat that provides both adequate space and shelter for turkeys is more important than the number of predators.(22) Blaming the fisher may be the easy thing for us to do, but the long-term solution to increasing turkey numbers may ultimately depend on man’s activities, as well as good habitat management.(23)

Geographic range

Body length: 90–120 cm / 35–47 in (males), 75–95 cm / 30–37 in (females)
Tail length: 37–41 cm / 14.5–16 in (males), 31–36 cm / 12–14 in (females)
Weight: 3.5–6.0 kg / 8–13 lb (males), 2.0–2.5 kg / 4–6 lb (females)
Lifespan: Up to 7 years (wild), up to 10 years (captivity)
Range: Northern forests of North America.
Conservation status: Least concern
Subfamily: Guloninae
References

  1. Mass Audubon. “About Fishers”. Accessed October 21, 2019.
  2. Powell, R.A. (May 8, 1981). Martes pennanti (PDF)Mammalian Species. The American Society of Mammalogists (156): 1–6. doi:10.2307/3504050. JSTOR 3504050. pp. 4–6. Archived from the original (PDF) on October 30, 2005. Accessed October 21, 2011.
  3. Koepfli, Klaus-Peter; Deere, Kerry A; Slater, Graham J; Begg, Colleen; Begg, Keith; Grassman, Lon; Lucherini, Mauro; Veron, Geraldine; Wayne, Robert K (February 14, 2008). “Multigene phylogeny of the Mustelidae: Resolving relationships, tempo and biogeographic history of a mammalian adaptive radiation”. BMC Biology. 6 (10): 10. doi:10.1186/1741-7007-6-10. PMC 2276185. PMID 18275614.
  4. Rhines, C. 2003. Martes pennanti (On-line), Animal Diversity Web. Accessed February 22, 2021.
  5. Powell, Roger A. (November 1993). “The Fisher: Life History, Ecology, and Behavior”. University of Minnesota Press. ISBN 978-0-8166-2266-5.
  6. Burt, William Henry. A field guide to the mammals: North America north of Mexico. Vol. 5. Houghton Mifflin Harcourt, 1976, p. 55.
  7. Feldhamer, George A.; Thompson, Bruce C.; Chapman, Joseph A. (2003). “Wild mammals of North America: biology, management, and conservation“. pp. 635–649. ISBN 978-0-8018-7416-1. Accessed September 12, 2020.
  8. Pattie, Donald L.; Fisher, Chris C. (1999). Mammals of Alberta. Edmonton: Lone Pine Pub. p. 82.
  9. Kurta, A. 1995. “Mammals of the Great Lakes Region”. Ann Arbor: University of Michigan Press.
  10. Novak, Milan. “Furbearer harvests in North America, 1600-1984”. Ministry of Natural Resources, 1987.
  11. Gabriel, Mourad W., et al. Anticoagulant rodenticides on our public and community lands: spatial distribution of exposure and poisoning of a rare forest carnivore. PloS one 7.7 (2012): e40163.
  12. Gabriel, Mourad W., et al. “Patterns of natural and human-caused mortality factors of a rare forest carnivore, the fisher (Pekania pennanti) in California.” PLoS One 10.11 (2015): e0140640.
  13. The Center for Biological Diversity. May 14, 2020. “Trump Administration Denies Endangered Species Protection for Pacific Fisher Across Most of Species’ Range”. Accessed June 08, 2020.
  14. San Diego Union-Tribune. June 12, 2008. “Weasel-like fishers rebound; backyard pets become prey”. Archived from the original on October 9, 2011. Accessed June 08, 2020.
  15. O’Brian, Brian. Boston Globe. August 25, 2005. “On the wild side: Once nearly extinct, weasel-like fishers thrive in the suburbs, where their ravenous feeding habits threaten family pets”. Accessed June 08, 2020.
  16. Orff, Eric B. New Hampshire Fish and Wildlife. “The Fisher: New Hampshire’s Rodney Dangerfield”. Accessed June 08, 2020.
  17. McNeil, Darin J., et al. Diets of fishers (Pekania pennanti) and evidence of intraspecific consumption in Pennsylvania“. The American Midland Naturalist 177.2 (2017): 200-210. p. 204.
  18. Orff, Eric B. New Hampshire Fish and Wildlife. “New Hampshire Weasels”. Accessed June 08, 2020.
  19. WCVB News. July 1, 2014. “Family says boy, 12, attacked by fisher cat”. Accessed June 08, 2020.
  20. Martin, Chris. New Hampshire Public Radio. March 13, 2015. “Something Wild: The Maligned Fisher”.  Accessed December 25, 2020.
  21. Steve Sorensen. Jamestown Gazette. June 18, 2018. Fishers—No Threat to Our Turkey Population. Accessed March 16, 2021.
  22. Ken Perrotte. National Wild Turkey Federation. 4 Facts about Declining Turkey Populations. Accessed March 16, 2021.
  23. James Earl Kennamer, Ph. D.. National Wild Turkey Federation. Wild Turkeys and Predators: What’s the Real Problem?. Accessed March 16, 2021.

What Are Mustelids?

American Mink | Badgers | Ferret-Badgers | Fisher | Grisons | Martens | Otters | PolecatsTayra | Weasels | Wolverine