This is a draft conservation strategy proposed by the State of Idaho. Cooperators include: Idaho Department of Fish and Game, Idaho Department of Parks and Recreation, Bureau of Land Management, Regions 1 and 4 of the U.S. Forest Service, and U.S. Fish and Wildlife Service. There are similar conservation strategies proposed for the lynx and wolverine.

"Generally, fisher populations have not markedly recovered from population reductions in the western habitats. Populations of fisher have remained at low numbers or are absent throughout much of their historical range in Washington, Oregon, California, Idaho, and Montana. The fisher population in British Columbia has also been at low numbers (Banci, pers. comm.). In the western United States, fishers appear most common in the southern Sierra Nevada of California, in northwestern California, in northern Idaho, and northwestern Montana." P. 4

"Historically, fishers probably occurred throughout the forested regions of Idaho, possibly as far south as the Boise and Payette River drainages (Maj and Garton 1994). Over-trapping and habitat loss due to extensive fires in 1910 and 1934 were most likely responsible for the decline of fisher in the state (Jones 1991). By the 1950’s and early 1960’s, fishers were considered extinct or extremely rare in Idaho (Williams 1962a, b). A reintroduction program was initiated in the early 1960’s releasing 39 fishers in 1962-1963 at 3 release sites in north-central Idaho. The effort was apparently successful, as trappers in the area were inadvertently capturing fishers by the late 1970’s. Limited expansion to the north may be occurring from this northcentral Idaho population (J. Jones pers. comm., C. Harris pers. comm.). Still, fishers probably do not occur more than 20 miles south of the Salmon River, and few fishers are reported north of Wallace and Interstate 90." P. 4

"Habitat loss is thought to be a major factor in the historical reduction of populations which occurred in the early 1900s. Remaining populations are limited in size, and may be isolated from other populations by distance and by the lack of suitable habitats in which to disperse. Productivity and density of northern Rocky fisher populations may be low, possibly due in part to low habitat quality. Loss of preferred habitat within existing populations could reduce productivity and density even further, increasing threats to the viability of these isolated populations. Additionally, forest management activities and development of forest lands results in increased density of roads into fisher habitat and existing fisher populations. This may lead to increases in mortality, primarily through increases in incidental trapping as these areas become accessible to trappers." P. 6

"In addition to habitat loss, trapping is though to have been the major factor leading to the historic declines in fisher populations. Fisher populations are sensitive to even light trapping pressure and populations such as the limited, low density populations that may occupy Idaho may be even more sensitive to any factor which increases mortality. Although fisher trapping seasons are closed in Idaho, incidental trapping mortality may limit populations in the state." p. 6

"Isolation of populations reduces demographic and genetic exchange, increasing the susceptibility of the population to extinction processes, and decreasing the probability of recolonization. Successful colonization of vacant, suitable habitats is unlikely when suitable habitats are highly dispersed across a mosaic of unsuitable or hostile habitats, without the presence of travel corridors. Anthropogenic barriers to dispersal include habitat alteration by forest practices, urban and agricultural development, and major roadways. Loss of forested riparian habitats is a particularly important impact affecting fisher persistence because of the importance of this habitat to fisher movement, foraging, and resting." P. 8

"Longterm fisher persistence may be threatened by habitat modifications resulting in isolation or fragmentation within and between regional populations." P. 9

"The reduction of habitat quality and connectivity due to natural or anthropogenic factors may result in larger spatial requirements of individual fishers, and an overall decrease in density and productivity of the population. Fisher home ranges in north-central Idaho were 2 to 11 times greater than home ranges reported in other regions (Jones 1991), even when using the same analysis technique (Heinemeyer 1993). This may indicate that present habitats support lower density fisher populations as compared to other regions." P. 10

"Roads pose an additional threat by increasing access to previously remote habitats and populations. The probability of trapping and the vulnerability to trapping is probably directly related to roads and ease of access." P. 10

"Preferred habitats in Idaho were closed canopy, late-seral, mesic forests, in close proximity to water. These habitats were frequently used as rest sites, probably due to high occurrence of large-diameter trees, logs and snags... Large-diameter logs were used by Idaho fishers for resting, particularly in winter when these ground level sites would provide increased thermal protection. Snags also provided resting sites for fisher in Idaho. (Jones 1991, Jones and Garton 1994)." P. 11

"Loss of preferred habitat or habitat connectivity within a fisher home range would reduce the availability of resting, foraging, and denning sites, and may require individuals travel further and through unsuitable or hostile habitats to meet life requirements." P. 12

"In Idaho, where fishers are protected, Luque (1983) estimated that at least 167 animals were inadvertently trapped over a 5-year period in sets made for marten, coyote and possibly bobcat." P. 12

"Although there is little data, density and natality rates may be lower and mortality rates may be higher for fishers in some western habitats than in habitats elsewhere in North America (reviewed in Heinemeyer and Jones 1994). Consequently, fishers populations in western habitats may be even more sensitive to the increased mortality cause by trapping." P. 13

"Predation susceptibility is likely increased to animals traveling through (dispersing) or residing in habitats of reduced quality." P. 14

"Habitat protection measures implemented for the conservation of anadromous fish may begin to protect critical riparian areas and the integrity of watersheds, but it is unlikely these guidelines will adequately maintain the habitat potential for fishers throughout the current and historical distribution of the species in Idaho." P. 14

"The low densities of fishers in general, and possibly of northern Rocky Mountain population in particular, may make populations more sensitive to natural or anthropogenic caused increases in mortality and habitat alteration. Low density populations are also more susceptible to extinction processes." P. 15

These subpopulations face not only the threats inherent to their small size and isolation, but the threats inherent to their geographic penisulearity as discussed above." P. 17