Fisher

Page last updated: 05/11/2024

(Pekania pennanti)

Fisher in summer coat by Emily Brouwer
Alternate winter coat: Link 1, Link 2
A rare leucistic fisher: Link 1

The fisher (sometimes misspelled as “fischer”), also known as the pekan, or misleadingly called a “fisher cat”, is a forest-dwelling mustelid native to North America. Both fisher and fisher cat are misnomers, given they do not catch fish and have no relation to cats.(1) The latter name can also lead some people to confuse the fisher with the fishing cat—which is actually a cat that catches fish. Both fishers and fisher are used as plural forms of the species, though the latter tends to be more popular with trappers and fur farmers.

The origin of the name fisher is not known for certain, but it is probably 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. In French, the pelt of a European polecat is also called fiche or fichet.(2) The “cat” half of their colloquial name is probably a superficial comparison to felines.

The fisher was previously placed with the martens in the genus Martes, until a study from 2008 using DNA sequences discovered that other species of Martes are genetically closer to the wolverine than to the fisher. This finding classifies Martes as paraphyletic. As a result, the fisher was reclassified in the separate genus Pekania.(3) Current studies suggest that the fisher is more closely related to the wolverine and tayra than to martens, further supporting its classification in a distinct genus.(4)

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 tricoloured 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)

The fisher can be distinguished from the often confused North American marten by its larger size, proportionately smaller ears, and the throat markings being pure white, when present at all.

Plantar glands

Like most marten species, the fisher has plantar glands within whorls of hair on their hind paws that emit a distinctive odour.(5)(6) The hairs appear as small dark circular patches on the large segmented centre pad (known as the metacarpal pad).

The plantar glands of pregnant female fishers enlarge to >10mm during January through May, and reduce in size (<10 mm) during June after giving birth. On males, the glands increase in size from <15 mm in December to >30mm in May. Reduction of the gland size is complete by June. Because these glands enlarge near and during mating season, it is hypothesised they serve the purpose of creating a trail of scent for fishers to locate each other for mating.(6) A photo showing off the whorls of dark hair associated with plantar glands.

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.(7) 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. They prefer areas with many hollow trees and continuous overhead cover, with greater than 80% coverage—avoiding areas with less than 50% coverage.(8)

Behaviour

Fishers are most active at dawn and night. They are believed to be solitary animals that only associate when mating. During all times of the year, fishers use “resting sites” such as logs, hollow trees, stumps, holes in the ground, brush piles, and nests of branches. Ground burrows tend to be used during winter, and tree nests are used all year, but primarily in the spring and autumn. Fishers use snow dens during winter, which are burrows under the snow with long and narrow tunnels leading to them.(7)

Reproduction

Female fishers are sexually mature after one year of age, with breeding season lasting from late March to early April. After fertilisation, 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.(9) Females then enter oestrus seven to ten days later before the breeding cycle resumes.(10)

The kits are born blind and helpless, but begin to crawl after three weeks. They open their eyes about seven weeks later,(11) 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.(10)

Diet

The fisher is an opportunistic predator and mainly feeds on small herbivorous mammals, birds, insects, nuts, berries, carrion, and sometimes other carnivores.(7) Despite their name they do not catch fish. 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.(8) This is in contrast to the exaggerated misconception where the fisher is said to flip a porcupine onto its back and “scoop out its belly like a ripe melon”.(12)

Predators

Although adult fishers are generally safe from predation, young fishers can occasionally fall prey to hawks, red foxes, lynx, and bobcats.(13)

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)(14)

Secondary exposure to pesticides

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 (known as the Pacific fisher or West Coast fisher, though they are not considered a distinct or subspecies of Pekania pennanti) are exposed to and killed by anticoagulant rodenticides associated with illegal marijuana cultivation.(15) 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.(16)

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.(17) In 2022, the Center for Biological Diversity and their allies sued the U.S. Fish and Wildlife Service for denying the Pacific fisher endangered species protection.(18)

Behavioural myths, rumours, and scapegoating

There are many beliefs about the fisher that are rarely backed by evidence beyond scaremongering and hearsay. Despite being a very elusive mustelid that few in the general public can identify or distinguish from other animals at a glance, it is not uncommon to hear exaggerated claims or sweeping generalisations about their behaviour and psychology, which is especially pervasive in the North American northeast.

The fact that many still believe the myth that the fisher habitually screams is in itself a case of mistaken identity that can lead to false accusations. The sheer amount of regurgitated rumours surrounding this mustelid has conditioned many people to fear or loathe its existence without question.

Fishers do not habitually scream

We often come across claims that the fisher habitually “screams like a banshee” or “screams like someone being murdered”, yet we have found no credible evidence of anyone actually witnessing a fisher opening its mouth to do this. There are people on places like YouTube perpetuating this belief by claiming the screams we hear in their videos are that of the fisher’s. However, apart from the fact that these claims are based on speculation since we never actually see the animal in any of these videos, the fisher is generally a silent mustelid that rarely gives its location. These sounds are often made by the red fox (Vulpes vulpes).(19) In fact, here is a video on YouTube that demonstrates a red fox scream. Here is another.

The only credible videos we have come across with a fisher “screaming” are of kits that are distressed or calling for their mother,(20)(21) which is not uncommon of young mammals and is likely something they stop doing as adults. As they mature, they will snarl when aggravated.(22) None of these sounds fit the description of the blood-curdling screams that tend to be reported. What makes the screaming claims even more dubious, is that we have come across claims of people hearing similar screams in areas where the fisher does not live but the red fox does, such as the United Kingdom.(23)

Given the lack of credible evidence of fishers screaming compared to red foxes, as well as critically assessing their behavioural and geographical differences, and the location of some of these screaming reports, we believe the claim that fishers are the source of these startling vocalisations likely stems from little more than urban legend due to mistaken identity.

Fishers do not frequently eat domestic cats

Another common rumour is that the fisher is a major predator of domestic cats.(24)(25) Sometimes state wildlife parks and even state government websites about local wildlife will seemly take for granted this unsubstantiated hearsay of the lay public.(26) Despite what some locals have claimed to have witnessed or caught, one or a few incidents of attacks on cats does not necessarily mean such attacks are happening frequently throughout the fisher’s range. The fisher is an opportunistic predator and does not seek out one animal in particular. Their capture of cats is likely incidental to the pursuit of any suitable prey. They are also far from the only predator of cats—coyotes being far more of a concern.(27)

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.(28) In 2011, an informal unfinished study in upstate New York found no cat remains in 24 scat or stomach samples, and an earlier published study found no trace of cat in 226 Massachusetts samples.(27) In 2017, a study in the U.S. state of Pennsylvania revealed similar results to the New Hampshire study.(29) Despite these data, the fisher continues to be largely blamed for missing cats. Wildlife biologist Eric Orff 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.”(30)

These studies suggest that while fishers can and have preyed on cats, the claim that they frequently do is likely exaggerated—the fisher being a convenient scapegoat for other, more likely explanations. Many claims also tend to be based on mere speculation, such as leaping to the conclusion that a missing cat was taken by a fisher without witnessing them doing so, second-hand identification, or assuming the prey one saw a fisher carry off was a cat.

Further, given that few people have seen or taken the time to objectively learn about the elusive fisher prior to an incident, and that mustelids are commonly misidentified by even those who claim to know how to identify them, cases of mistaken identity cannot be ruled out. Even if every study did find cat remains in the stomach and scat samples of fishers, without further examination, we could not discount the possibility that some of the cats were already dead (e.g., roadkill) before they were consumed.

It is the sole responsibility of a cat owner to mind their pet’s welfare. Rather than blame or demonise the fisher for existing in its natural range and likely hunting as they have long before cats were introduced to North America, if we are truly concerned for their safety, we should either keep our cats inside at dawn or at night or supervise them whenever they are let outside during these periods. All things considered, a free-roaming cat (especially one without a collar) is probably more likely to be taken by a fellow human being who assumed they were lost or abandoned than a fisher.

Fishers do not frequently attack humans

Unless a fisher is threatened, cornered, suffering from injury or illness, attacks on humans are extremely rare. There have been a few isolated claims of attacks on humans.(31)(32) However, similar to attacks on domestic cats, some of these allegations may or may not be true, since some incidents may not have been thoroughly investigated to confirm the attacker was a fisher. Even if this were the case, as with cats, one or a few isolated attacks on humans does not mean such incidents are likely to occur or are happening all the time.

Fishers are simply trying to find food to survive, though like practically any wild animal they may react aggressively to a perceived threat when startled. To lower the chances of such encounters, it is best to restrict access to food waste, pets, pet foods, and domestic fowl.

Fishers are not the main threat to wild turkey populations

Some believe the fisher is the main cause for the decline of wild turkey populations in the United States. This is likely yet another unsubstantiated belief about the fisher that make them a convenient target of misdirected anger. While it is possible for fishers to prey on turkeys, the act is seldom common enough to be a significant threat to their numbers. They are also not always successful.(33) A 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.(28) The fisher is also far from the only predator of turkeys.(34)

According to an article on the National Wild Turkey Federation’s website, 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. The belief is that a quality habitat that provides both adequate space and shelter for turkeys is more important than the number of predators.(35)

Blaming the fisher for the decline of wild turkeys may be the easy thing for us to do whenever they are caught in the act, but it only tells half the story. The long-term solution to increasing turkey numbers may ultimately depend on man’s activities as well as good habitat management.(36)

Geographic range

Total length: 90–120 cm / 35–47 in (males), 75–95 cm / 30–37 in (females)
Tail length: 30–42 cm / 12–17 in
Weight: 3.5–6.0 kg / 8–13 lb (males), 2.0–2.5 kg / 4–6 lb (females)(7)
Lifespan: Up to 7 years (wild)(37)(38), up to 14 years (captivity)
Range: Northern forests of North America.
Conservation status: Least concern
Subfamily: Guloninae
References

  1. Mass Audubon. “About Fishers”. Accessed 21 October, 2019.
  2. Powell, R.A. 08 May, 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 30 October, 2005. Accessed 05 October, 2024.
  3. Koepfli, Klaus-Peter; Deere, Kerry A; Slater, Graham J; Begg, Colleen; Begg, Keith; Grassman, Lon; Lucherini, Mauro; Veron, Geraldine; Wayne, Robert K (14 February, 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. Samuels, Joshua X., and Jennifer Cavin. The earliest known fisher (Mustelidae), a new species from the Rattlesnake Formation of Oregon. Journal of Vertebrate Paleontology 33.2 (2013): 448-454.
  5. Naturally Curious with Mary Holland. 22 August, 2010. Scent Glands – Welcome to a photographic journey through the woods, fields and marshes of New England“. Accessed 06 October, 2024.
  6. Powell, R. A., S. W. Buskirk, and W. J. Zielinski. Fisher and marten: Martes pennant and Martes americana. Wild mammals of North America: Biology, management and conservation. John Hopkins University Press Baltimore, 2003. 635-649. pp. 636-639.
  7. Rhines, C. 2003. Martes pennanti (On-line), Animal Diversity Web. Accessed 22 February, 2021.
  8. Powell, Roger A. (November 1993). “The Fisher: Life History, Ecology, and Behavior”. University of Minnesota Press. ISBN 978-0-8166-2266-5.
  9. Burt, William Henry. A field guide to the mammals: North America north of Mexico. Vol. 5. Houghton Mifflin Harcourt, 1976, p. 55.
  10. 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 12 September, 2020.
  11. Pattie, Donald L.; Fisher, Chris C. (1999). Mammals of Alberta. Edmonton: Lone Pine Pub. p. 82.
  12. Doyle, Brian. High Country News6 March, 2006. “Fishering”.  Accessed 28 June, 2021.
  13. Kurta, A. 1995. “Mammals of the Great Lakes Region”. Ann Arbor: University of Michigan Press.
  14. Novak, Milan. “Furbearer harvests in North America, 1600-1984”. Ministry of Natural Resources, 1987.
  15. 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.
  16. 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.
  17. The Center for Biological Diversity. 14 May, 2020. “Trump Administration Denies Endangered Species Protection for Pacific Fisher Across Most of Species’ Range”. Accessed 08 June, 2020.
  18. The Center for Biological Diversity. Fisher. Accessed 05 July, 2023.
  19. Martin, Chris. New Hampshire Public Radio. 13 March, 2015. “Something Wild: The Maligned Fisher”.  Accessed 25 December, 2020.
  20. Christian Latino. YouTube. 14 June, 2018. Fisher Cat Cry. Accessed 03 November, 2022.
  21. Rbrongo2. YouTube. 16 May, 2020. Baby Fisher sounds. Accessed 03 November, 2022.
  22. Capecast. YouTube. 20 July, 2011. Fishers-The Cape’s most elusive animal. Accessed 14 January, 2023.
  23. Varela, Charlotte. The Wildlife Trust for Lancashire, Manchester and North Merseyside. 23 January, 2019. Communal living and screams in the night: The secret lives of foxes. Accessed 02 January, 2023.
  24. San Diego Union-Tribune. 12 June, 2008. “Weasel-like fishers rebound; backyard pets become prey”. Archived from the original on October 9, 2011. Accessed 08 June, 2020.
  25. O’Brian, Brian. Boston Globe. 25 August, 2005. “On the wild side: Once nearly extinct, weasel-like fishers thrive in the suburbs, where their ravenous feeding habits threaten family pets”. Accessed 08 June, 2020.
  26. Division of Fisheries and Wildlife. Mass.gov. Learn about fishers. Accessed 24 January, 2023.
  27. Kays, Roland. The New York Times. 6 April, 2011. “Do Fishers Really Eat Cats?”.  Archived from the original on 9 April, 2011. Accessed 17 July, 2021.
  28. Orff, Eric B. New Hampshire Fish and Wildlife. “The Fisher: New Hampshire’s Rodney Dangerfield”. Accessed 08 June, 2020.
  29. 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.
  30. Orff, Eric B. New Hampshire Fish and Wildlife. “New Hampshire’s Weasels”. Accessed 08 June, 2020.
  31. WCVB News. 1 July, 2014. “Family says boy, 12, attacked by fisher cat”. Accessed 08 June, 2020.
  32. FOXProvidence.com. 23 June, 2009. “Fisher Cat Attacks Child at Bus Stop”. Archived from the original on 6 March, 2011. Retrieved 17 July, 2021.
  33. Sorensen, Steve. Jamestown Gazette. 18 June, 2018. Fishers—No Threat to Our Turkey Population. Accessed 16 March, 2021.
  34. Miller, James E., and Bruce D. Leopold. Population influences: predators. The wild turkey: biology and management. Stackpole Books, Harrisburg, Pennsylvania, USA (1992): 119-128.
  35. Perrotte, Ken. National Wild Turkey Federation. 4 Facts about Declining Turkey Populations. Archived from the original on June 03, 2022. Accessed 16 March, 2021.
  36. Kennamer, James E. National Wild Turkey Federation. 25 August, 2021.Wild Turkeys and Predators: What’s the real problem facing wild turkeys?. Accessed 05 January, 2023.
  37. New York Zoological Society (1971). Bronx Zoo (Report).
  38. Basic Facts About Fishers. Defenders of Wildlife. Retrieved June 3, 2016.

What Are Mustelids?

Badgers | Ferret-Badgers | Fisher | Grisons | Martens | Otters | Tayra | Weasels | Wolverine