South Fork Kern River and Valley The
South Fork Kern River is the heart of the preserve and the South Fork Valley. The river begins at elevation in the
Inyo National Forest at Mulkey Meadows, named after Cyrus Mulkey, sheriff of Inyo County, California from 1871 to 1874. The river flows down the South Fork Valley, through the Audubon Kern River Preserve to Lake Isabella at elevation. The South Fork Valley, only a few miles wide and in length, is at the southern end of the
Sierra Nevada Mountains in northeastern Kern County. Although the valley was the first area settled in the county, it contains the largest contiguous riparian forest still remaining in the state. Rare wildflowers include the
alkali mariposa lily. Listed by
California Native Plant Society as "rare, threatened or endangered in California and elsewhere", it has been observed near the South Fork Kern River, as well as the surrounding counties and in the state of Nevada. It is a perennial bulb that blooms in April and May, and is threatened by grazing, trampling, road construction, urbanization and horticultural collecting. Water diversions can also impact this primarily wetland species.
Bird species The streamside habitat provides nesting sites for riparian-dependent bird species: The federally threatened
western yellow-billed cuckoo, endangered in California; the
brown-crested flycatcher, a cavity-nester; the
yellow warbler, the
yellow-breasted chat, and the southwestern willow flycatcher. The federally listed endangered southwestern willow flycatcher has small populations in the preserve and is closely monitored by Audubon volunteers and staff. The US Fish and Wildlife Service designated
critical habitat for the southwestern willow flycatcher which includes of the South Fork Kern River and excludes Hafenfeld Ranch which has the conservation easement in place. Another notable bird is the
summer tanager. The summer tanager breeds in lowlands along streams and is known as a
bee and wasp specialist. The summer tanager will remove the bee's stinger before ingesting by rubbing the bee on a branch. The least Bell's vireo is a species that will hopefully reestablish nesting in the South Fork Kern River Valley. It is one of four subspecies of
Bell's vireo, which disappeared from California's Central Valley by the 1960s, and has been federally listed as endangered since 1986. The US Fish and Wildlife Service's 5-year review of least Bell's vireo, dated September 2006, attributes the primary cause of population declines to loss of riparian habitat in California. Another threat listed by the review is from the
brown-headed cowbird which lays its eggs in other birds' nests, called
brood parasiteism. The Southern Sierra Research Station, which conducts research on the Kern River Preserve, has a cowbird eradication program which has reduced the rate of parasitism to 20 percent from 60 to 70 percent (percentage of willow flycatcher nests studied by Southern Sierra Research Station staff).
Mammals, amphibians, reptiles and insects Common mammals include mule deer, coyote,
dusky-footed woodrat,
long-tailed weasel, California ground squirrel, American black bear, and bobcat. Uncommon species include mountain lion and an introduced species of beaver. There are 50 species of mammals found on the Kern River Preserve. There are three species of amphibians and 24 species of reptiles, including the common
garter snake,
California kingsnake, several lizard species and the
California toad. The only venomous snake at the preserve is the
Northern Pacific rattlesnake. Also found at the preserve is the
Pacific pond turtle, a species of concern in California and listed as endangered in
Washington state. The South Fork Valley is unique in California, as three of the ten
floristic provinces in the nation meet and overlap here. The floristic provinces are:
Great Basin Desert, Mojave Desert, and Californian Province (in which one finds numerous ecotypes: grassland, riparian forest, oak woodland, interior chaparral, mixed conifer, sequoia, red fir, subalpine.) The resulting diversity is evident in the numbers of species: There are 31 species
dragonfly, of and 53 species of
butterfly, including the alkali skipper (
grass skipper) and the rare San Emigdio blue butterfly. The San Emigdio blue butterfly is a species of concern due to its limited local range consisting of Southern California from Inyo County south through the
Mojave Desert,
San Joaquin Valley,
Bouquet and Mint canyons of
Los Angeles County. ==Scientific research==