FWS Focus

Overview

Characteristics
Overview

The fishers of the Southern Sierra Nevada Distinct Population Segment are medium-sized mammals that are classified in the same family as weasels, mink, martens and otters. These fishers have a light brown to black fur coat, with white patches on its chest. They have a broad head, pointy snout, bushy tail and small ears. Males are larger than females. They are most often found in forested areas, with a large tree canopy cover that contain a mix of conifer and California black oak trees. They are mostly found on federal lands managed by the U.S. Forest Service and National Park Service.

They face several threats, including wildfire, climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
, tree mortality, predation, toxicants, collisions with vehicles and potential effects associated with small population size. The Southern Sierra Nevada Distinct Population Segment of fisher was listed as endangered in 2020. 

Scientific Name

Pekania pennanti
Common Name
Fisher
FWS Category
Mammals
Kingdom

Location in Taxonomic Tree

Genus

Identification Numbers

TSN:

Characteristics

Characteristic category

Food

Characteristics
Food

Fishers are opportunistic hunters and primarily eat squirrels, mice and birds. New research shows the fishers also eat fungi. 

Characteristic category

Life Cycle

Characteristics
Lifespan

Fishers live to be about 10 years of age. 

Reproduction

The breeding period for the Southern Sierra Nevada Distinct Population Segment of fisher begins in late February and lasts through April. Females give birth about one year later in dens. While fishers tend to stay in a single den, some females may use five or more den sites throughout a season. Once weaned, the kits stay with the female, utilizing multiple structures within the female’s home range, until juveniles disperse in the fall or winter following their birth. Kits become independent of their mother and develop their own home ranges by 1 year of age and leave their home dens around March. Males disperse further than females.

Characteristic category

Habitat

Characteristics
Habitat

They are most often found in forested areas with a large tree canopy cover that contain a mix of conifer and California black oak trees. They are mostly found on federal lands managed by the U.S. Forest Service and National Park Service. The species has been sighted in Mariposa, Madera, Fresno, Tulare and Kern counties, California.

Throughout their range, fishers use tree cavities for denning, and they select denning and resting sites in forests that have high canopy cover, a lot of snags and downed wood.

Forest

A dense growth of trees and underbrush covering a large tract.

Mountain

A landmass that projects conspicuously above its surroundings and is higher than a hill.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The fishers of the Southern Sierra Nevada Distinct Population Segment are medium-sized mammals that are classified in the same family as weasels, mink, martens and otters. Males are larger than females. 

Color & Pattern

These fishers have a light brown to black fur coat, with white patches on its chest. They have a broad head, pointy snout, bushy tail and small ears.

Geography

Characteristics
Range

These fishers are found in low- to mid-elevation forests from the Tuolumne River in Yosemite National Park, south to the Greenhorn Mountains within Sequoia National Forest. The species has been sighted in Mariposa, Madera, Fresno, Tulare and Kern counties, California.

Launch Interactive Map

Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

41 Items