Nevada Fish & Wildlife Office
Pacific Southwest Region

Fisher

(Martes pennanti)

Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Martes
Species: pennanti
Size: Males = 35 to 47 inches and 6.6 to 13.2 lbs
Females = 29 to 37 inches and 3.3 to 5.5 lbs
Lifespan: avg 10 years
Feed: birds, squirrels, mice, shrews, voles, reptiles, insects, plants, fruit, and dead animals
Habitat: dense canopy closure, large diameter trees (conifers and hardwoods) and snags with cavities and other deformities, large diameter down wood, multiple canopy layers
 

Official Status:

  Candidate - California/Nevada Region (Region 8) - West coast DPS
Status Undefined - Mountain-Prairie Region (Region 6) - Northern Rocky Mountains DPS
 

Life History:

Populations of fishers have declined in all Canadian provinces and states except the Yukon and in the extreme northeastern United States (Maine, New Hampshire, and Vermont). In the western United States and Canadian Provinces, the number of fishers has been greatly reduced and their populations fragmented.

The fisher is light brown to dark blackish-brown, with the face, neck, and shoulders sometimes being slightly gray. The chest and underside often has irregular white patches. The fisher has a long body with short legs and a long bushy tail. At 6.6 to 13.2 pounds, male fishers weigh about twice as much as females (3.3 to 5.5 pounds). Males range in length from 35 to 47 inches while females range from 29 to 37 inches in length. Fishers from the Pacific States may weigh less than fishers in the eastern United States.

Except during the breeding season, fishers are solitary animals. The breeding season for the fisher is generally from late February to the end of April. Female fishers raise 1 to 3 kits, which are weaned by 10 weeks old. When they are 1 year of age, kits have established their own home ranges and are no longer dependent upon adults.

Fishers have a diverse diet that includes birds, squirrels, mice, shrews, voles, reptiles, insects, plants, fruit, and dead animals. Small and mid-sized mammals are the most common prey items eaten by fishers in the Pacific States. Fishers search for prey in forested stands, avoiding openings.

 

Distribution and Habitat:

 

A resident of coniferous and mixed coniferous forests, the fisher once occurred throughout much of Canada, the northern United States, and the western United States. Fishers are no longer believed to occupy the lower mainland of British Columbia and the area west of Okanogan extending down to Washington.

The West Coast Distinct Population Segment includes the states of Washington, Oregon, and California. Fishers are known to occur in Oregon and California; fishers were re-introduced into the Olympic Peninsula of Washington in January and March of 2008.

Fishers use late-successional habitats with dense canopy closure, large diameter trees (conifers and hardwoods) and snags with cavities and other deformities, large diameter down wood, multiple canopy layers. Late-successional coniferous or mixed forests that contain key habitat and structural components provide the most suitable fisher habitat because they provide abundant potential den sites and preferred prey species. The physical structure of the forest and prey associated with forest structures are thought to be the critical features that explain fisher habitat use, rather than specific forest types. The West Coast population of the fisher inhabits forested areas from sea level along the California Oregon Coast to approximately 1,970 to 8,530 ft in the Sierra Nevada.

 

Threats:

 

Fisher populations have declined primarily due to loss of habitat from timber harvest activities and trapping.

 

Actions / Current Information:

 


Candidate Notice of Review Documents
Date Citation Page Title
11/09/2009 74 FR 57803 57878 Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions (external link)
12/10/2008 73 FR 75175 75244 Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule (external link)
12/06/2007 72 FR 69033 69106 Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule (external link)
09/12/2006 71 FR 53755 53835 Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions (external link)
05/11/2005 70 FR 24869 24934 Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule (external link)

» Federal Register Documents

Most Recent Federal Register Documents

Date

Citation Page

Title

03/18/13   U.S. Fish and Wildlife Service Initiates Review of the
Status of West Coast Fisher Population

11/09/2009

74 FR 57803 57878

Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions (external link)

12/10/2008

73 FR 75175 75244

Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule (external link)

12/06/2007

72 FR 69033 69106

Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule (external link)

09/12/2006

71 FR 53755 53835

Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions (external link)

05/11/2005

70 FR 24869 24934

Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions; Proposed Rule

» Action Plans

Action Plans

Date

Title

2010-2014

Fishers-west coast DPS action plan

» Recovery

Recovery Plan Information Search

•  Information Search FAQs

No recovery information is available for the fisher.

» Critical Habitat

No critical habitat rules have been published for the fisher.

» Conservation Plans

Candidate Conservation Agreements with Assurances (CCAA): (learn more) (Showing 1 of 1 )

CCAA Plan Summaries

Sierra Pacific Industries for Fisher for the Stirling Management Area

» Petitions

Most Recent Petition Findings (Showing 3 of 3 )

Date

Citation Page

Title

Finding

04/08/2004

69 FR 18769 18792

Endangered and Threatened Wildlife and Plants; 12-month Finding for a Petition to List the West Coast Distinct Population Segment of the Fisher (Martes pennanti )

· Notice 12 month petition finding, Warranted but precluded

07/10/2003

68 FR 41169 41174

Endangered and Threatened Wildlife and Plants; 90-day Finding for a Petition To List a Distinct Population Segment of the Fisher in Its West Coast Range as Endangered and To Designate Critical Habitat

· Notice 90-day Petition Finding, Substantial

03/01/1996

61 FR 8016 8018

ETWP; 90-Day Finding for a Petition To List the Fisher in the Western Untied States as Threatened

· Notice 90-day Petition Finding, Not substantial

 
Last updated: April 16, 2014