Threatened and Endangered Species
of the Pit River Watershed

The Pit River Watershed is well known for supporting some of the best hunting and fishing in the state. It is less known, however, for the presence of several threatened and endangered (T&E) fish, bird, mammal, plant, and invertebrate species. Some of these species can be found in other regions of the state or adjacent states (e.g., northern spotted owl, bank swallow, wolverine).  Other species occur primarily in the watershed and in adjacent states, but are less frequent and abundant in other parts of California (e.g., greater sandhill crane). Finally, a handful of species are only found in the Pit River watershed (e.g., Modoc sucker, Goose Lake redband, Shasta crayfish). Depending on the species distribution in California and other states, the species may be listed under the federal Endangered Species Act (FESA) or California Endangered Species Act (CESA).  Both Acts afford the species certain regulatory protection.  

Swainson’s hawks often nest in trees along riparian corridors or in isolated trees located near suitable foraging habitat (low growing agriculture crops and grassland vegetation). 

Throughout its range, the northern spotted owl occurs primarily in late seral-stage conifer forests (Forsman et al. 1984, Gutierrez 1996). Studies of habitat use indicate that owls generally select late seral-stage forests equal to or more than expected, and early seral-stage forests less than expected, although individual owls and pairs sometimes deviate from this general pattern  (Forsman 1980, Forsman et al. 1984, Sisco and Gutierrez 1990, Gutierrez 1996).  At the landscape level, home range size was found to be negatively correlated with the proportion of late seral-stage forest in the home range, and breeding densities were negatively correlated with the amount of forest fragmentation (Carey et al. 1990,1992).

The many forest types occupied by northern spotted owls, including Douglas-fir, western hemlock, grand fir, white fir, ponderosa pine, Shasta red fir, western red cedar, redwood, and mixed conifer and conifer/hardwood forests have led to an emphasis on forest structure in studies of habitat use.  Thus, optimal northern spotted owl habitat has been characterized as uneven-aged forest with a multilayered canopy, high canopy closure, large overstory trees, and a considerable degree of decadence, such as trees with broken tops and cavities for nesting, dead snags, decaying logs, and woody debris on the forest floor (Dawson et al. 1987, LaHaye 1988, Thomas et al. 1990, Gutierrez 1996).

The little willow flycatcher primarily nests in dense willow thickets in montane meadows and along streams.  This species forages in riparian and meadow habitats during the nesting season.  It arrives on the breeding grounds in May and June and migrates to southern Mexico and Central America in August (Harris et al. 1988, Zeiner et al. 1990).

The greater sandhill crane nests in open areas of wet meadows.  These areas are often interspersed with emergent marsh.  Sandhill cranes usually build their nests over shallow water.  This species forages in emergent marsh and meadow habitats during the nesting season (California Department of  Fish and Game 1997).  During winter, sandhill cranes forage in pastures, flooded grain fields, and seasonal wetlands (Zeiner et al. 1990a).  Breeding activity begins in April and ends in August (Zeiner et al. 1990). 

Bald eagle nesting territories in California are found primarily in ponderosa pine and mixed conifer forests.  Nest sites are always associated with a lake, reservoir, river, or other large water body that supports abundant fish, waterfowl, or other water bird prey.  Nest trees are usually located in mature and old-growth stands within 1 mile of water.  Nests are constructed in trees that provide an unobstructed view of the water body; nest trees are typically the dominant or codominant tree in the surrounding stand (Lehman 1979).  In California, breeding bald eagles are restricted primarily to northern counties.  Bald eagles forage from hunting perches at large bodies of water or rivers with abundant fish.  Breeding activity begins as early as February and ends in July (Zeiner et al. 1990).

The American peregrine falcon nests on vertical cliffs with large potholes or ledges that is inaccessible to land predators.  Because this species preys primarily on birds, nest sites are usually located near areas that support large populations of birds, such as coastal areas or wetlands with (Monk and Walton 1988).  Peregrine falcons may travel long distances from their nesting grounds to forage near or within forested habitat (Grinnell and Miller 1944, California Department of Fish and Game 1980).  Breeding activity begins as early as March and ends in August (Zeiner et al. 1990a).

In the northern Sierra Nevada wolverines inhabit mixed conifer, red fir, and lodgepole pine habitats and probably also uses subalpine conifer, alpine dwarf-shrub, wet meadows, and montane riparian habitats (White and Barrett 1979, Zeiner et al. 1990).  In the southern Sierra Nevada, wolverines inhabit lodgepole pine, red fir, mixed conifer, subalpine conifer, alpine dwarf-shrub, barren, and probably wet meadows, montane chaparral, and Jeffrey pine habitats (Zeiner et al.1990).  California wolverine use high elevation cirque basins for den sites and forage in open to sparse tree habitats on the ground, in trees, burrows, among rocks, and sometimes in shallow water (Copeland 1996, Zeiner et al. 1990b, Ruggiero et al. 1994).  Wolverines are generally considered to avoid areas disturbed by logging, road building, and general human use.