Red Hills (Tuolumne County)
Encyclopedia
The Red Hills are a mountain range in Tuolumne County
, California
.
Elevations within the Red Hills vary between 750 and 1,750 feet above sea level. Slopes of the hills themselves vary from about 30% to 75%.
as an Area of Critical Environmental Concern
. The Red Hills Management Area consists of 7,100 acres (slightly more than 11 square miles) of public land located near the intersection of California State Route 49
and California State Route 120
, just south of the historic town of Chinese Camp, California
in Tuolumne County.
The entire Red Hills Management Area has been designated as an ACEC. The purpose of the designation is to protect the rare plant species found there, the unusual serpentine soil
s that provide habitat for unique flora of the area, habitat for the rare minnow
known as the Red Hills roach and to protect bald eagle wintering habitat.
s associated with the emplacement of the Sierra Nevada batholith
, east of the metamorphic belt.
The Management Area includes much of the Tuolumne ultramafic complex, one of the largest exposures of serpentine rocks in the Sierra Nevada metamorphic belt. Nearly the entire area is underlain by dunite
, a variety of peridotite
consisting of dark green olivine
and minor chromite
, which has been partly or entirely serpentinized to antigorite magnesite
-magnetite
. The dunite intruded into andesite pillow breccia
s and flows of the Peñon Blanco volcanic formation, which crops out near the northeast and southern boundaries of the Management Area. The intrusion of ultramafic material occurred along crustal weaknesses associated with the Bear Mountain fault, a northwestward trending thrust fault
that dips steeply to the northeast, and has over 10,000 feet of vertical displacement. The fault zone is on the southwestern boundary of the Management Area, and is believed to have once penetrated the earth's crust down to the mantle, a probable source of the peridotite.
Other geologic features of the area include northeastward trending dikes that consists of massive, dark brown, hornblende
-plagioclase
diorite
which intruded into the dunite bedrock. A swarm of several dikes occurs in the southeast portion of the Management Area. Some of the dikes exceed one mile in length. Amphibolite
and chert
tectonic blocks also occur in the dunite near the area's southern and western boundaries.
Tertiary
and Pleistocene
alluvium
consisting of sand, gravel, pebbles, and cobbles has accumulated in Six Bit and Poor Man's Gulches in the northern and eastern portions of the Management Area.
. Virtually the only tree species in the Red Hills is Foothill pine (Pinus sabiniana), which is found throughout the Red Hills in low densities. Buckbrush
(Ceanothus cuneatus) comprises a majority of the shrub cover. Other shrubs include Toyon (Heteromeles arbutifolia), Coffee berry
(Rhamnus californica tomentella), Chamise
(Adenostoma fasciculatum), Hollyleaf redberry
(Rhamnus crocea ilicifolia), California yerba santa
(Eriodictyon californicum), and Manzanitas
(Arctostaphylos spp.).
Native perennials constitute a large percentage of the grass cover in the Red Hills. This is in contrast to similar elevations in the foothills, without serpentine substrates, where native perennials have been mostly replaced by exotic annuals. Important native perennial species include California oniongrass
(Melica californica), Big squirreltail grass (Sitanion jubatum) and Pine bluegrass
(Poa secunda). Disturbed areas, including burned areas, have a typical array of Mediterranean annual grasses
.
Herbaceous plants provide a spectacular wildflower bloom in the spring that attracts tourists, amateur naturalists, and classes from educational institutions. Although most of the species comprising the display are widespread on and off serpentine, some (in addition to the rare species discussed below) are strict serpentine endemics (e.g., Streptanthus polygaloides).
indicating that the United States Fish and Wildlife Service
feels it has accumulated sufficient evidence to list these species. These plants are the California verbena
(Verbena californica), Rawhide Hill onion
(Allium tuolumnense). A third plant species, Layne's butterweed
(Senecio layneae), has already been listed as a threatened species.
Two plants that had been designated as federal candidate category 2 species were eliminated from the list of candidate species when the U.S. Fish and Wildlife Service changed its rules for the inclusion of species as candidates in 1996. Congdon's lomatium
(Lomatium congdonii) and the Red Hills soaproot
(Chlorogalum grandiflorum) are locally common throughout the Red Hills favoring north slopes and ridgetops respectively. Congdon's lomatium is only known from the Red Hills and the Peoria Valley area. Red Hills soaproot is also found in El Dorado County, California
on serpentine and gabbro
.
An additional species proposed for federal listing occurs on private lands just west of Chinese Camp and within a mile of the public land. Chinese Camp brodiaea
(Brodiaea pallida) grows near a low gradient drainage in soils that remain wet late into the growing season. This species has not been located on the public lands of the Red Hills.
Another plant, Hoover's butterweed
(Senecio clevelandii var. heterophyllus) has been included on the California Native Plant Society
's Watch List. It grows with the California verbena in riparian zone
s. It may be recognized as a separate taxon
that is endemic to the Red Hills, or it may be included as a single taxon with plants found in the Coast Ranges.
, jackrabbits, rodents. Coyote
s, bobcat
s and fox can also be found in the Red Hills.
88 bird species have been observed in the Red Hills. Some common species include mourning dove
, acorn woodpecker
, ash-throated flycatcher, scrub jay, wrentit, plain titmouse, bushtit, Bewick's wren, and house finch
. Valley quail
and mourning doves are the major game birds in the Red Hills. An abundant insect population supports insectivorous birds including western kingbirds, ash- throated flycatcher, tree swallow
s, barn swallow
s, black phoebes, and others. Raptor
s include the red-tailed hawk, Cooper's hawk, prairie falcon
, and great horned owl
. Fish-eating birds seen in the Red Hills include the belted kingfisher and great blue heron
. Roadrunner
s can also be found.
Reptiles and amphibians are rarely observed in the Red Hills but interestingly two rare species are represented (see below).
Fish in the Red Hills, found in Six Bit Gulch and Poor Man's Creek, include the green sunfish
, large-mouth bass, Sacramento sucker, and the mosquito fish. These fish are predators or competitors with the Red Hills roach, a rare taxon of Minnow
(discussed below). The presence of these mostly introduced species may limit the roach population.
Rare fauna: Four sensitive species of animals are known from the Red Hills. Wintering bald eagle
s roost along the shores of Don Pedro Reservoir and have been observed where Six Bit Gulch enters the lake. As many as 20 bald eagles have been sighted during the winter on the shores of Don Pedro Reservoir, roosting in stands of foothill pines.
Although the Red Hills has no perennial streams, it has a number of intermittent streams that have spring fed reaches and pools. Two sensitive riparian animal species are associated with these areas, Hesperoleucus symmetricus (California roach, a minnow; the distinctive Red Hills population has been called the Red Hills roach) and Rana boylii (foothill yellow legged frog).
The Red Hills roach is found in abundance in several pools of permanent water located along the intermittent streams which drain into Six Bit Gulch and Poor Man,s Gulch. It is thought that the permanent pools are spring-fed. During the dry part of the year the fish are confined to these permanent pools surviving in warm shallow water until spring when they move upstream to spawn. A recent study by ichthyologists at the University of California, Davis, and the California Department of Fish and Game has indicated that the Red Hills variety of California roach has unique morphologic characteristics, which make them noticeably different from other roach populations, notably a chisel lip. The chisel lip is used to scrape algae, a major food source, off submerged rocks.
The foothill yellow-legged frog has been found in the western portion of the Red Hills in the Andrews Creek drainage. The western pond turtle
has been found in the eastern portion of the Red Hills in Poor Man's Gulch. Both are rare species, formerly candidates for federal listing.
The placer gold produced from this district was recovered by ground sluicing and hydraulic mining
in earlier years, and by dragline dredging in the 1930s and 1940s. In the 1850s, during the great California Gold Rush, Chinese laborers, with their legendary patience and thoroughness, mined much of the placer gold within Six Bit Gulch, a major drainage channel that courses through the natural area. The dredging of Six Bit Gulch and Poor Man's Gulch produced over $100,000 worth of gold.
Tuolumne County, California
Tuolumne County is a county in the Sierra Nevada of the U.S. state of California. The northern half of Yosemite National Park is located in the eastern part of the county. As of the 2010 census, the population was 55,365, up from 54,501 at the 2000 census...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
.
Elevations within the Red Hills vary between 750 and 1,750 feet above sea level. Slopes of the hills themselves vary from about 30% to 75%.
Red Hills Area of Critical Environmental Concern
The Red Hills contain the The Red Hills of Tuolumne County Area of Critical Environmental Concern (ACEC), managed by the Bureau of Land ManagementBureau of Land Management
The Bureau of Land Management is an agency within the United States Department of the Interior which administers America's public lands, totaling approximately , or one-eighth of the landmass of the country. The BLM also manages of subsurface mineral estate underlying federal, state and private...
as an Area of Critical Environmental Concern
Area of Critical Environmental Concern
Areas of Critical Environmental Concern is a conservation ecology program in the western United States, managed by the Bureau of Land Management. The ACEC program was conceived in the 1976 Federal Lands Policy and Management Act , which established the first conservation ecology mandate for the BLM...
. The Red Hills Management Area consists of 7,100 acres (slightly more than 11 square miles) of public land located near the intersection of California State Route 49
California State Route 49
State Route 49 is a north–south state highway in the U.S. state of California that passes through many historic mining communities of the 1849 California gold rush. Highway 49 is numbered after the "49ers", the waves of immigrants who swept into the area looking for gold, and a portion of it...
and California State Route 120
California State Route 120
State Route 120 , in northern California, runs between the Central Valley near Manteca, through Yosemite National Park, and ends at U.S. Route 6 in Mono County.-Route description:...
, just south of the historic town of Chinese Camp, California
Chinese Camp, California
Chinese Camp is a census-designated place in Tuolumne County, California, United States. The population was 126 at the 2010 census, down from 146 at the 2000 census. It lies in the grassy foothills of the Sierra Nevada near the southern end of California's Gold Country.-History:Chinese Camp is the...
in Tuolumne County.
The entire Red Hills Management Area has been designated as an ACEC. The purpose of the designation is to protect the rare plant species found there, the unusual serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s that provide habitat for unique flora of the area, habitat for the rare minnow
Minnow
Minnow is a general term used to refer to small freshwater and saltwater fish, especially those used as bait fish or for fishing bait. More specifically, it refers to small freshwater fish of the carp family.-True minnows:...
known as the Red Hills roach and to protect bald eagle wintering habitat.
Geology
The Red Hills Management Area is located within the western tectonic block of the Sierra Nevada metamorphic belt. Within this block are Upper Jurassic volcanic and sedimentary rocks of island arc derivation which were highly deformed and weakly metamorphosed during the Nevada orogeny. These rocks were then intruded by plutonPluton
A pluton in geology is a body of intrusive igneous rock that crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, dikes, sills, laccoliths, lopoliths, and other igneous bodies...
s associated with the emplacement of the Sierra Nevada batholith
Sierra Nevada Batholith
The Sierra Nevada Batholith is a large batholith which forms the core of the Sierra Nevada mountain range in California, USA, exposed at the surface as granite....
, east of the metamorphic belt.
The Management Area includes much of the Tuolumne ultramafic complex, one of the largest exposures of serpentine rocks in the Sierra Nevada metamorphic belt. Nearly the entire area is underlain by dunite
Dunite
Dunite is an igneous, plutonic rock, of ultramafic composition, with coarse-grained or phaneritic texture. The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite and pyrope. Dunite is the olivine-rich end-member of the peridotite group...
, a variety of peridotite
Peridotite
A peridotite is a dense, coarse-grained igneous rock, consisting mostly of the minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium, reflecting the high proportions of magnesium-rich olivine, with appreciable iron...
consisting of dark green olivine
Olivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
and minor chromite
Chromite
Chromite is an iron chromium oxide: FeCr2O4. It is an oxide mineral belonging to the spinel group. Magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite ; substitution of aluminium occurs leading to hercynite .-Occurrence:Chromite is found in...
, which has been partly or entirely serpentinized to antigorite magnesite
Magnesite
Magnesite is magnesium carbonate, MgCO3. Iron substitutes for magnesium with a complete solution series with siderite, FeCO3. Calcium, manganese, cobalt, and nickel may also occur in small amounts...
-magnetite
Magnetite
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron oxide and the common chemical name is ferrous-ferric oxide. The formula for magnetite may also be written as FeO·Fe2O3, which is one part...
. The dunite intruded into andesite pillow breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
s and flows of the Peñon Blanco volcanic formation, which crops out near the northeast and southern boundaries of the Management Area. The intrusion of ultramafic material occurred along crustal weaknesses associated with the Bear Mountain fault, a northwestward trending thrust fault
Thrust fault
A thrust fault is a type of fault, or break in the Earth's crust across which there has been relative movement, in which rocks of lower stratigraphic position are pushed up and over higher strata. They are often recognized because they place older rocks above younger...
that dips steeply to the northeast, and has over 10,000 feet of vertical displacement. The fault zone is on the southwestern boundary of the Management Area, and is believed to have once penetrated the earth's crust down to the mantle, a probable source of the peridotite.
Other geologic features of the area include northeastward trending dikes that consists of massive, dark brown, hornblende
Hornblende
Hornblende is a complex inosilicate series of minerals .It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole....
-plagioclase
Plagioclase
Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...
diorite
Diorite
Diorite is a grey to dark grey intermediate intrusive igneous rock composed principally of plagioclase feldspar , biotite, hornblende, and/or pyroxene. It may contain small amounts of quartz, microcline and olivine. Zircon, apatite, sphene, magnetite, ilmenite and sulfides occur as accessory...
which intruded into the dunite bedrock. A swarm of several dikes occurs in the southeast portion of the Management Area. Some of the dikes exceed one mile in length. Amphibolite
Amphibolite
Amphibolite is the name given to a rock consisting mainly of hornblende amphibole, the use of the term being restricted, however, to metamorphic rocks. The modern terminology for a holocrystalline plutonic igneous rocks composed primarily of hornblende amphibole is a hornblendite, which are...
and chert
Chert
Chert is a fine-grained silica-rich microcrystalline, cryptocrystalline or microfibrous sedimentary rock that may contain small fossils. It varies greatly in color , but most often manifests as gray, brown, grayish brown and light green to rusty red; its color is an expression of trace elements...
tectonic blocks also occur in the dunite near the area's southern and western boundaries.
Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
and Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
alluvium
Alluvium
Alluvium is loose, unconsolidated soil or sediments, eroded, deposited, and reshaped by water in some form in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel...
consisting of sand, gravel, pebbles, and cobbles has accumulated in Six Bit and Poor Man's Gulches in the northern and eastern portions of the Management Area.
Flora
The Red Hills are vegetated mostly by a foothill pine-buckbrush chaparral/woodlandCalifornia interior chaparral and woodlands
The California interior chaparral and woodlands ecoregion covers in an elliptical ring around the California Central Valley. It occurs on hills and mountains ranging from to . It is part of the Mediterranean forests, woodlands, and scrub biome, with cool, wet winters and hot, dry summers...
. Virtually the only tree species in the Red Hills is Foothill pine (Pinus sabiniana), which is found throughout the Red Hills in low densities. Buckbrush
Ceanothus cuneatus
Ceanothus cuneatus is a species of flowering shrub known by the common names Buckbrush and wedgeleaf ceanothus.-Distribution:...
(Ceanothus cuneatus) comprises a majority of the shrub cover. Other shrubs include Toyon (Heteromeles arbutifolia), Coffee berry
Rhamnus californica
Rhamnus californica , is called coffeeberry because its berries contain seeds which look like coffee beans—it is also called California buckthorn...
(Rhamnus californica tomentella), Chamise
Adenostoma fasciculatum
Adenostoma fasciculatum is a flowering plant native to California and northern Baja California. This shrub is one of the most widespread plants of the chaparral biome.-Description:...
(Adenostoma fasciculatum), Hollyleaf redberry
Rhamnus crocea
Rhamnus crocea is a species of buckthorn. There are two subspecies: Rhamnus crocea subsp. crocea and Rhamnus crocea subsp. pilosa . It is native to California, Arizona, and Baja California....
(Rhamnus crocea ilicifolia), California yerba santa
Eriodictyon californicum
Eriodictyon californicum is a species of plant within the Hydrophyllaceae family. It is also known as Yerba Santa, Mountain Balm, Consumptive's Weed and Bear Weed.-Distribution:...
(Eriodictyon californicum), and Manzanitas
Arctostaphylos
Arctostaphylos is a genus of plants comprised by the manzanitas and bearberries. They are shrubs or small trees.There are about 60 species of Arctostaphylos, ranging from ground-hugging arctic, coastal, and mountain species to small trees up to 6 m tall. Most are evergreen , with small oval...
(Arctostaphylos spp.).
Native perennials constitute a large percentage of the grass cover in the Red Hills. This is in contrast to similar elevations in the foothills, without serpentine substrates, where native perennials have been mostly replaced by exotic annuals. Important native perennial species include California oniongrass
Melica californica
Melica californica is a species of grass known by the common name California melic.-Distribution:This grass is native to Oregon and California, where it grows in many types of habitat, from mountain forests to open grassland at sea level...
(Melica californica), Big squirreltail grass (Sitanion jubatum) and Pine bluegrass
Poa secunda
Poa secunda is a widespread species of grass native to North America. It is highly resistant to drought conditions, and provides excellent fodder.-External links:**...
(Poa secunda). Disturbed areas, including burned areas, have a typical array of Mediterranean annual grasses
Invasive grasses of North America
Grasses are one of the most abundant floras on all continents except Antarctica. Their divergence is estimated to have taken place 200 million years ago. Humans have intentionally and unintentionally introduced these species to North America through travel and trade. On the North American plains,...
.
Herbaceous plants provide a spectacular wildflower bloom in the spring that attracts tourists, amateur naturalists, and classes from educational institutions. Although most of the species comprising the display are widespread on and off serpentine, some (in addition to the rare species discussed below) are strict serpentine endemics (e.g., Streptanthus polygaloides).
Sensitive plants
Sensitive plants: Five plants which occur on the public lands of the Red Hills are considered sensitive species by BLM due to their rarity. Two of the plants have been proposed for listing under the Endangered Species ActEndangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
indicating that the United States Fish and Wildlife Service
United States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
feels it has accumulated sufficient evidence to list these species. These plants are the California verbena
Verbena californica
Verbena californica is a rare species of verbena known by the common names California vervain and Red Hills vervain. This flower is endemic to Tuolumne County, California, where it is known from ten or eleven occurrences in the Red Hills, a section of the Sierra Nevada foothills near Chinese Camp....
(Verbena californica), Rawhide Hill onion
Allium tuolumnense
Allium tuolumnense is a rare species of wild onion known by the common name Rawhide Hill onion. It is endemic to Tuolumne County, California, where it is known only from a small section of the Sierra Nevada foothills. It is a plant of serpentine soils...
(Allium tuolumnense). A third plant species, Layne's butterweed
Senecio
Senecio is a genus of the daisy family that includes ragworts and groundsels. The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters...
(Senecio layneae), has already been listed as a threatened species.
- California verbena is a Red Hills endemic, meaning it is found nowhere else in the world. Its distribution in the Red Hills is confined to the short stream reaches that remain moist year round because of ground water seepSeepA petroleum seep is a place where natural liquid or gaseous hydrocarbons escape to the earth's atmosphere and surface, normally under low pressure or flow. Seeps generally occur above either terrestrial or offshore petroleum accumulation structures...
age. - The Rawhide Hill onion has many, mostly small, colonies in the Red Hills. Rawhide Hill onion is confined to areas with sparse vegetation, south facing slopes with shallow soils, and intermittent drainages.
- Layne's butterweed is the only federally listed plant species in the Red Hills at this time. There are only a few very small occurrences of this member of the sunflower family in the Red Hills. Here as elsewhere, this species is often associated with disturbances like roadcuts. Senecio layneae is also found in El Dorado County on serpentine and gabbro.
Two plants that had been designated as federal candidate category 2 species were eliminated from the list of candidate species when the U.S. Fish and Wildlife Service changed its rules for the inclusion of species as candidates in 1996. Congdon's lomatium
Lomatium congdonii
Lomatium congdonii, known by the common names Mariposa desertparsley and Congdon's lomatium, is a species of flowering plant in the carrot family .-Description:...
(Lomatium congdonii) and the Red Hills soaproot
Chlorogalum grandiflorum
Chlorogalum grandiflorum is a species of flowering plant known by the common name Red Hills soap plant. It is endemic to the Sierra Nevada foothills, such as the Red Hills , of California, where it grows in chaparral, woodland, and forest.-Description:This uncommon perennial wildflower grows from a...
(Chlorogalum grandiflorum) are locally common throughout the Red Hills favoring north slopes and ridgetops respectively. Congdon's lomatium is only known from the Red Hills and the Peoria Valley area. Red Hills soaproot is also found in El Dorado County, California
El Dorado County, California
El Dorado County is a county located in the historic Gold Country in the Sierra Nevada Mountains and foothills of the U.S. state of California. The 2010 population was 181,058. The El Dorado county seat is in Placerville....
on serpentine and gabbro
Gabbro
Gabbro refers to a large group of dark, coarse-grained, intrusive mafic igneous rocks chemically equivalent to basalt. The rocks are plutonic, formed when molten magma is trapped beneath the Earth's surface and cools into a crystalline mass....
.
An additional species proposed for federal listing occurs on private lands just west of Chinese Camp and within a mile of the public land. Chinese Camp brodiaea
Brodiaea pallida
Brodiaea pallida is a rare species of flowering plant in the cluster-lily genus known by the common name Chinese Camp brodiaea. It is endemic to California, where it is known from a two populations along the border between Tuolumne and Calaveras Counties...
(Brodiaea pallida) grows near a low gradient drainage in soils that remain wet late into the growing season. This species has not been located on the public lands of the Red Hills.
Another plant, Hoover's butterweed
Senecio
Senecio is a genus of the daisy family that includes ragworts and groundsels. The flower heads are normally rayed, completely yellow, and the heads are borne in branched clusters...
(Senecio clevelandii var. heterophyllus) has been included on the California Native Plant Society
California Native Plant Society
The California Native Plant Society is a California not-for-profit organization that seeks to increase understanding of California's native flora and to preserve that flora. Its "paramount purpose is to preserve wild plants".-History:...
's Watch List. It grows with the California verbena in riparian zone
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...
s. It may be recognized as a separate taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
that is endemic to the Red Hills, or it may be included as a single taxon with plants found in the Coast Ranges.
Fauna
In the Red Hills buckbrush and other shrubs provide browse and seeds for small populations of mammals, including mule deerMule Deer
The mule deer is a deer indigenous to western North America. The Mule Deer gets its name from its large mule-like ears. There are believed to be several subspecies, including the black-tailed deer...
, jackrabbits, rodents. Coyote
Coyote
The coyote , also known as the American jackal or the prairie wolf, is a species of canine found throughout North and Central America, ranging from Panama in the south, north through Mexico, the United States and Canada...
s, bobcat
Bobcat
The bobcat is a North American mammal of the cat family Felidae, appearing during the Irvingtonian stage of around 1.8 million years ago . With twelve recognized subspecies, it ranges from southern Canada to northern Mexico, including most of the continental United States...
s and fox can also be found in the Red Hills.
88 bird species have been observed in the Red Hills. Some common species include mourning dove
Mourning Dove
The Mourning Dove is a member of the dove family . The bird is also called the Turtle Dove or the American Mourning Dove or Rain Dove, and formerly was known as the Carolina Pigeon or Carolina Turtledove. It is one of the most abundant and widespread of all North American birds...
, acorn woodpecker
Acorn Woodpecker
The Acorn woodpecker is a medium-sized woodpecker, 21 cm long with an average weight of 85 g.-Description:...
, ash-throated flycatcher, scrub jay, wrentit, plain titmouse, bushtit, Bewick's wren, and house finch
House Finch
The House Finch is a bird in the finch family Fringillidae, which is found in North America. This species and the other "American rosefinches" are usually placed in the rosefinch genus Carpodacus...
. Valley quail
Quail
Quail is a collective name for several genera of mid-sized birds generally considered in the order Galliformes. Old World quail are found in the family Phasianidae, while New World quail are found in the family Odontophoridae...
and mourning doves are the major game birds in the Red Hills. An abundant insect population supports insectivorous birds including western kingbirds, ash- throated flycatcher, tree swallow
Tree Swallow
The Tree Swallow, Tachycineta bicolor, is a migratory passerine bird that breeds in North America and winters in Mexico, Central America and the Caribbean. It is a very rare vagrant to western Europe....
s, barn swallow
Barn Swallow
The Barn Swallow is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts, a long, deeply forked tail and curved, pointed wings. It is found in Europe, Asia, Africa and the Americas...
s, black phoebes, and others. Raptor
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
s include the red-tailed hawk, Cooper's hawk, prairie falcon
Prairie Falcon
The Prairie Falcon is a medium-sized falcon of western North America.It is about the size of a Peregrine Falcon or a crow, with an average length of 40 cm , wingspan of 1 metre , and weight of 720 g...
, and great horned owl
Great Horned Owl
The Great Horned Owl, , also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas.-Description:...
. Fish-eating birds seen in the Red Hills include the belted kingfisher and great blue heron
Great Blue Heron
The Great Blue Heron is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North and Central America as well as the West Indies and the Galápagos Islands. It is a rare vagrant to Europe, with records from Spain, the Azores and England...
. Roadrunner
Roadrunner
Roadrunners are birds of the genus Geococcyx.Roadrunner or Road Runner may also refer to:* Wile E. Coyote and Road Runner, an animated character based on the bird** The Road Runner Show, compiled cartoons including the character...
s can also be found.
Reptiles and amphibians are rarely observed in the Red Hills but interestingly two rare species are represented (see below).
Fish in the Red Hills, found in Six Bit Gulch and Poor Man's Creek, include the green sunfish
Green sunfish
The green sunfish is a species of freshwater fish in the sunfish family of order Perciformes. A panfish popular with anglers, the green sunfish is also kept as an aquarium fish by hobbyists. They are usually caught by accident, while fishing for other game fish...
, large-mouth bass, Sacramento sucker, and the mosquito fish. These fish are predators or competitors with the Red Hills roach, a rare taxon of Minnow
Minnow
Minnow is a general term used to refer to small freshwater and saltwater fish, especially those used as bait fish or for fishing bait. More specifically, it refers to small freshwater fish of the carp family.-True minnows:...
(discussed below). The presence of these mostly introduced species may limit the roach population.
Rare fauna: Four sensitive species of animals are known from the Red Hills. Wintering bald eagle
Bald Eagle
The Bald Eagle is a bird of prey found in North America. It is the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle...
s roost along the shores of Don Pedro Reservoir and have been observed where Six Bit Gulch enters the lake. As many as 20 bald eagles have been sighted during the winter on the shores of Don Pedro Reservoir, roosting in stands of foothill pines.
Although the Red Hills has no perennial streams, it has a number of intermittent streams that have spring fed reaches and pools. Two sensitive riparian animal species are associated with these areas, Hesperoleucus symmetricus (California roach, a minnow; the distinctive Red Hills population has been called the Red Hills roach) and Rana boylii (foothill yellow legged frog).
The Red Hills roach is found in abundance in several pools of permanent water located along the intermittent streams which drain into Six Bit Gulch and Poor Man,s Gulch. It is thought that the permanent pools are spring-fed. During the dry part of the year the fish are confined to these permanent pools surviving in warm shallow water until spring when they move upstream to spawn. A recent study by ichthyologists at the University of California, Davis, and the California Department of Fish and Game has indicated that the Red Hills variety of California roach has unique morphologic characteristics, which make them noticeably different from other roach populations, notably a chisel lip. The chisel lip is used to scrape algae, a major food source, off submerged rocks.
The foothill yellow-legged frog has been found in the western portion of the Red Hills in the Andrews Creek drainage. The western pond turtle
Western pond turtle
The western pond turtle , or Pacific pond turtle is a small to medium-sized turtle growing to approximately 20 cm in carapace length. It is limited to the west coast of the United States of America and Mexico, ranging from western Washington state to northern Baja California...
has been found in the eastern portion of the Red Hills in Poor Man's Gulch. Both are rare species, formerly candidates for federal listing.
Gold
Placer gold occurs in stream channel deposits within the natural area, primarily Six Bit Gulch and Poor Man's Gulch, mostly washed in from the north..The placer gold produced from this district was recovered by ground sluicing and hydraulic mining
Hydraulic mining
Hydraulic mining, or hydraulicking, is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold.-Precursor - ground...
in earlier years, and by dragline dredging in the 1930s and 1940s. In the 1850s, during the great California Gold Rush, Chinese laborers, with their legendary patience and thoroughness, mined much of the placer gold within Six Bit Gulch, a major drainage channel that courses through the natural area. The dredging of Six Bit Gulch and Poor Man's Gulch produced over $100,000 worth of gold.
See also
- California interior chaparral and woodlandsCalifornia interior chaparral and woodlandsThe California interior chaparral and woodlands ecoregion covers in an elliptical ring around the California Central Valley. It occurs on hills and mountains ranging from to . It is part of the Mediterranean forests, woodlands, and scrub biome, with cool, wet winters and hot, dry summers...
- Category: Flora of California
- Category: Bureau of Land Management areas in California