Santa Clara Valley Habitat Conservation Plan

CENTRAL CALIFORNIA COAST STEELHEAD
(Oncorhynchus mykiss)

Photo courtesy of Bill Mitchell

Species Group: Fish

Range: Coastal populations of winter steelhead are found from the Russian River in Sonoma County south to Aptos Creek in Santa Cruz County. In Santa Clara County this species inhabits San Francisquito, Guadalupe, Coyote Creeks, as well as many of their major tributaries.

Habitat: Small, shaded pools of cool, low-flow stream reaches; spawning sites with a gravel base and sufficient flow velocity; winter habitat including small tributaries, backwater areas, and other low flow areas.

Steelhead trout belong to the family Salmonidae which includes all salmon, trout, and chars. Steelhead are the anadromous form of rainbow trout. The term anadromous refers to fish species born in fresh water streams that migrate to the ocean for their adult phase. Steelhead are born and spend their first 1-3 years of life in fresh water streams before emigrating to the ocean where most of their adult growth occurs. After spending between one to four growing seasons in the ocean, steelhead return to their native fresh water stream to spawn. Unlike salmon, steelhead do not necessarily die after spawning, are able to spawn more than once, and can live up to eight years.

Unique Facts: The condition of Central California Coast steelhead populations is an indicator of overall stream and river health because they use all portions of a river system, and require cool, clean water.

Status: Federal Threatened

Threats: The primary threat to Central California Coast steelhead is urbanization, which has resulted in freshwater habitat loss and habitat degradation. This has resulted from human activities that discharge sediment and pollutants into waterways, inadequate stream flows from water diversions serving population centers, and blocked access to historic spawning and rearing areas due to dams or other migration barriers such as culverts. Due to impassable dams limiting access to historical spawning areas, NOAA Fisheries predicts that Central California Coast Steelhead will become endangered within the foreseeable future.

Conservation Legacy: Central California Coast steelhead are still present in most of the coastal streams in their historic range, though their abundance has been reduced and their distribution restricted.

The Santa Clara Valley Habitat Plan will contribute to the conservation and recovery of steelhead by protecting watershed functions that provide habitat for steelhead. Changes in flow releases proposed under the Three Creeks HCP (formerly FAHCE) will improve habitat conditions for steelhead within the Study Area. Conservation of lands will protect upper watershed functions contributing to improved habitat conditions throughout riverine systems.

WESTERN BURROWING OWL
(Athene cunicularia hypugaea)

Species Group: Birds

Range: Occurs throughout the western United States and Mexico. Historically occurred in suitable lowland habitats throughout the San Francisco Bay Area, utilizing open valley floors and low sloping foothills. However, populations in the San Francisco Bay Area and along the California coast have been greatly reduced. Major remaining populations in California are in the Central and Imperial Valleys.

Habitat: Occupies areas with short and sparse vegetation and underground burrows. Habitat includes grasslands, deserts, sagebrush scrub, agricultural areas, earthen levees and berms, and urban vacant lots, as well as the margins of airports, golf courses, and roads.

Unique Facts: Burrowing owls often seek out nest sites where livestock manure is plentiful because they use it to line their nests and mask their scent from potential predators. The number of eggs laid by burrowing owls is proportionate to the amount of prey that is available. The probability that juvenile burrowing owls will survive to one year of age and breed is estimated to be less than one percent.

Status: State Bird Species of Special Concern; Federal protection under Migratory Bird Treaty Act

Threats: The most immediate threats to the burrowing owl are the conversion of grassland habitat to urban and agricultural uses, and the loss of suitable agricultural lands to development. Because western burrowing owls most commonly live in burrows created by California ground squirrels, their survival is also threatened the rodent eradication programs.

Conservation Legacy: Little information exists on the migratory routes, timing, and wintering areas of the California population of Burrowing Owls. Management activities to preserve existing burrowing owl populations include preventing disturbance during the nesting season, installing artificial burrows, and managing the vegetation around burrows with mowing or controlled grazing.

FRAGRANT FRITILLARY
(Fritillaria liliacea)

Species Group: Plants

Range: Only found in western central California from Sonoma/Solano counties south to Monterey County.

Habitat: Occurs in grasslands, woodland, and coastal scrub and in vernal pool areas. Typically occurs on serpentine soils and blooms from February to May. Serpentine grasslands in the study area are the most likely habitat for this species.

Unique Facts: The Fragrant Fritillary produces beautiful white flowers from bulbs and would be suitable for cultivation in the horticultural industry if it were not an endangered species.

Status: Not state or federally listed, but shown to be declining.

Threats: Fragrant fritillary is primarily threatened by loss of habitat to urban development and agriculture, competition from invasive non-native species, grazing, recreation, and feral pigs.

Conservation Legacy: With in the study area, suitable habitat for Fragrant fritillary is located in the foothills on the east and west sides of the valley floor. While no conservation actions are planned as part of the Santa Clara Valley Habitat Plan that target Fragrant fritillary specifically, ongoing and planned efforts to improve species that rely on serpentine soils in general should benefit the recovery of the species.

SAN JOAQUIN KIT FOX
(Vulpes macrotis mutica)

Species Group: Mammals

Range: Southern and western portions of the Central Valley and northern San Joaquin Valley. Occurs or may occur at low densities in Contra Costa, Alameda, San Joaquin, Monterey, San Benito, Santa Barbara, and Santa Clara counties.

Habitat: Grasslands, scrublands, vernal pool areas, alkali meadows, playas, and agricultural lands including row crops, irrigated pastures, orchards, vineyards, and grazed annual grasslands. Dens generally located in grassy, open areas.

Unique Facts: The San Joaquin kit fox is a subspecies of the kit fox (Vulpes macrotis), the smallest member of the dog family in North America. The San Joaquin Kit fox is the smallest fox in North America, only about 20 inches long and weighing about 5 pounds, smaller than most house cats. All kit foxes have relatively large ears to hear approaching predators and detect prey. San Joaquin kit foxes prey on small mammals, ground-nesting birds, and insects, and are subject to predation from coyote, non-native red foxes, domestic dogs, eagles, and large hawks.

Status: State Threatened; Federal Endangered

Threats: Fragmentation of habitat caused by barriers that impede movement (such as aqueducts and busy highways) is a serious threat to the San Joaquin Kit Fox. The use of pesticides to control rodents and other pests also threatens the kit fox, either directly by poisoning, or indirectly by reducing the amount of prey available for them to eat. The threat of kit fox being struck by vehicles is also high.

Conservation Legacy: Suitable habitat for the San Joaquin kit fox occurs within the Pacheco Watershed and South Santa Clara Valley Watershed. Within the Santa Clara Valley Habitat Plan study area, suitable habitat is limited to the southeastern portion and is primarily located on private lands south of Henry Coe State Park. The Pacheco-Santa Ana Watershed in southeastern Santa Clara County is an important wildlife corridor that supports the movement of interbreeding of kit fox between the San Luis Reservoir and Alameda and Contra Costa counties. While livestock grazing may negatively affect the amount and types of prey available to the kit fox, managed and moderate grazing may benefit the species by reducing vegetation which helps the kit fox to detect and avoid predators. The Nature Conservancy’s Mount Hamilton Project also includes land preservation activities in southeastern Santa Clara County intended to conserve this species.

GOLDEN EAGLE
(Aquila chrysaetos)

Gordon and Buff Corsi, CA Academy of Sciences

Species Group: Birds

Range: Found throughout much of western North America from Alaska to Mexico. Found throughout much of California except the Central Valley.

Habitat: Preferred habitat includes areas with favorable nest sites, a dependable food supply (small to medium mammals and birds), and broad expanses of open country for foraging. Favors open grasslands and oak savannah, with lesser numbers in oak woodland and open shrublands. Secluded cliffs with overhanging ledges and trees are used for nesting and cover.

Unique Facts: Golden eagles are the top avian predator in the grassland/savanna ecosystem of California’s central Coast Range. The slopes and valleys of the Diablo Range in eastern Alameda and Contra Costa Counties support the highest known density of Golden Eagle nesting territories in the world.

Status: State protected; Federal protection under the Bald Eagle and Golden Eagle Protection Act and Migratory Bird Treaty Act

Threats: While the numbers of Golden Eagles are reduced near human population centers, in general, the population seems to be stable. The primary threats to survival of the golden eagle include loss or alteration of foraging and nesting habitat from activities such as reclamation of grasslands for agriculture, urbanization, and the elimination of annual grassland habitat. The Golden Eagle is also threatened by human disturbance of nesting birds, and bird fatalities caused when the birds hit structures such as power facilities, buildings, and fences. The only known Golden eagle nest site in the study area is located on a PG&E transmission tower just south of San Jose.

Conservation Legacy: Historically, the Golden Eagle inhabited the foothills of Santa Clara County in large quantities due to large numbers of California ground squirrels on which to feed, and numerous roosting and nesting sites in rocky outcrops and forested valleys. Currently, there are no nesting sites and only two documented sightings of Golden Eagle in the study area (though additional individual sightings most likely have not have been recorded). Golden eagle management and conservation actions include habitat management, population enhancement, hazard management, controlling human activity in sensitive raptor areas, and education. Moderate cattle ranching that maintains low-height grasses and provides food for rodents and rabbits can also benefit the species. In addition, land preservation in the Diablo Range by agencies such as the Santa Clara Valley Open Space Authority, The Nature Conservancy, and California State Parks have indirectly benefited the Golden Eagle by preserving open space.

LEAST BELL’S VIREO
(Vireo belii pusillus)

Species Group: Birds

Range: A migratory species that breeds in North America and spends the winter along the Pacific Coast in southern Mexico. Historically, widespread throughout California, particularly in the Sacramento and San Joaquin valleys. An observation along Llagas Creek in 1997 was the first time this species had been seen in Santa Clara County in over 50 years.

Habitat: Nests along heavily vegetated waterways, especially riparian woodlands dominated by willow and cottonwood. Requires a dense shrub layer above the ground to nest. May also forage in adjacent scrub or chaparral habitat.

Unique Facts: In recent years, this species has been expanding from southern California into its historic range in northern California. In 2005, the first least Bell’s vireo nests in 60 years were documented in the Central Valley near Modesto where suitable habitat was restored.

Status: State Endangered; Federal Endangered and Protected under Migratory Bird Treaty Act

Threats: The Least Bell’s Vireo is dependent on dense riparian corridors (typically along watercourses) for successful breeding and scrub habitats adjacent to watercourses for foraging and nesting. The Least Bell’s Vireo is threatened by loss of breeding habitat from watercourse alteration caused by channelization, urbanization, and firewood cutting. The species is also threatened increases in populations of the brown-headed cowbird caused by residential development, agriculture, and grazing, which has increased competition for food and nesting sites, as well as nest parasitism.

Conservation Legacy: Breeding and foraging of the Least Bell’s Vireo is limited to riparian forest and scrub habitats in the Pacheco Creek/Uvas Creek/Llagas Creek watershed in southern Santa Clara County. While the Least Bell’s Vireo is rare is Santa Clara County, it is expected to increase its range northward into the study area during the permit term of the Santa Clara Valley Habitat Plan.

CENTRAL VALLEY FALL RUN CHINOOK SALMON
(Oncorhynchus tshawytscha)

2003 Jeff Kozlowski

Species Group: Fish

Range: Sacramento River, San Joaquin River, and tributaries of both systems. Also found in tributaries of south San Francisco Bay. In Santa Clara County, occurs in the Guadalupe River, Los Gatos Creek, Coyote Creek, and Penitencia Creek.

Habitat: Require cool, clear water with sufficient flow velocity and gravel substrate for spawning and incubation. Juveniles require cool, clear water as in riffles, runs, pools, and inundated floodplains with instream cover such as woody debris or boulders.

Unique Facts: Fall-run Chinook Salmon migrate from the Pacific Ocean to Central Valley rivers from approximately August to December. Adult Chinook salmon do not feed during this spawning migration.

Status: Federal Species of Concern

Threats: The decline of Chinook salmon is a result of degradation and loss of habitat, especially as a result of dams blocking historic access to spawning and rearing habitat. In addition, low water flows reduce suitable habitat areas and elevate water temperatures, affecting dissolved oxygen levels necessary for survival. These conditions stress eggs and rearing juveniles. Low flow levels also impede up- and down-stream migration by reducing water depth. Chinook Salmon are also impacted by fluctuating water temperatures resulting from reservoir operations, contaminants, predation by nonnative species, and interaction with hatchery stock.

Conservation Legacy: Chinook salmon is one of the most abundant salmon species in North America. There are approximately one thousand spawning populations of Chinook salmon on the North American coast from southeastern Alaska to California.

The Santa Clara Valley Habitat Plan will protect the habitats of Fall-run Chinook salmon currently migrating up the Guadalupe River, Los Gatos Creek, and Coyote Creek. With the installation of a fish passage facility at Metcalf Dam, it is reasonable to assume that Chinook will now be able to migrate all the way up Coyote Creek to the base of Anderson Dam. Changes in flow releases proposed under the Three Creeks HCP (formerly FAHCE) will improve habitat conditions for Chinook within the Study Area.

CALIFORNIA RED-LEGGED FROG
(Rana aurora draytonii)

2002 Pierre Fidenci

Species Group: Amphibians

Range: Santa Clara County hillsides, San Francisco Bay Area, and the Central Coast. Isolated populations occur in the Sierra Nevada and Northern Coast ranges.

Habitat: Breeding adults, larvae, tadpoles, and young frogs require deep, still, or slow-moving water with dense, shrubby vegetation occurring in streams, ponds, or marshes. As possible during dry weather, California red-legged frogs remain in or near water. As aquatic sites dry out, the frogs disperse and will travel up to one mile to other areas with water, or will take temporary shelter under boulders, logs, leaf litter, agricultural drains, watering troughs, small mammal burrows, incised stream channels, etc.

Unique Facts: Adapted to the Mediterranean climate of Northern California, Red-Legged Frogs migrate several miles to more permanent water sources like rivers and streams when breeding pools dry up in the summer.

Status: State Species of Special Concern; Federal Threatened

Threats: Threats to the California Red-Legged Frog are a result of degradation, fragmentation, and loss of habitat through degraded water quality, introduced predators and non-native plants, agriculture, mining, recreation, timber harvesting, water diversions, and poorly managed infrastructure maintenance activities, such as road construction and repair. These activities degrade California Red-Legged Frog habitat by increasing disturbance, reducing water quality, or increasing competition and predation pressure.

Conservation Legacy: In the 1990’s, the California Red-Legged Frog experienced a 70 percent reduction in its geographic range. This decline was primarily a result of habitat loss and alteration, and introduction of exotic predators. Today, the species continues to decline at a rapid rate. The California Red-Legged Frog has essentially disappeared from urbanized lowland areas of Santa Clara County and the brackish marshlands bordering San Francisco Bay, but are still found in foothill and mountain ranges throughout the County. Adult frogs have been observed in many creeks from this area, south to Henry W. Coe State Park. Approximately half of the occurrences in the study area are in creek and pond habitats in Henry W. Coe State Park. A significant portion of the remaining occurrences are on City of San Jose, Santa Clara Valley Water District, and Santa Clara County properties.

CALIFORNIA TIGER SALAMANDER
(Ambystoma californiense)

Species Group: Amphibians

Range: Santa Clara Valley, Sonoma, Alameda, and Santa Barbara counties and the Central Valley, Southern San Joaquin Valley, and Central Coast Range. Within the study area, occurrences are scattered throughout the study area and on both sides of the valley, with large clusters of occurrences in Henry W. Coe State Park and Joseph D. Grant County Park.

Habitat: California Tiger Salamander inhabit valley and foothill grasslands and the grassy understory of open woodlands, usually within one mile of water. Primary habitat requirements include underground sites such as ground squirrel and pocket gopher burrows for cover during the non-breeding season and aquatic sites such as ponds, vernal pools, and wetlands for breeding.

Unique Facts: Adults often spend 10 months or more underground and only emerge after rains to breed.

Status: State Species of Special Concern; Central California population (Sonoma County and Santa Barbara County) Federal Threatened

Threats: California Tiger Salamander populations have declined from the conversion of valley and foothill grassland and oak woodland habitats to urban and agricultural uses, resulting in habitat loss and fragmentation, the removal or fragmenting of vernal pool complexes, the elimination of refuge sites adjacent to breeding areas. Other threats include non-native species that prey on tiger salamander larvae, burrowing-mammal control programs, and vehicles encountered when the salamanders attempt to cross roads during migration.

Conservation Legacy: The California Tiger Salamander is endemic to California. Suitable habitat for the California Tiger Salamander is spread evenly throughout the undeveloped portions of the study area, primarily due to the even distribution of stock ponds and other aquatic habitat.

COYOTE CEANOTHUS
(Ceanothus ferrisae)

2005 Janell Hillman

Species Group: Plants

Range: Only found in Santa Clara County. All occurrences are in the Mt. Hamilton range within four miles of one another. Two locations, including the largest population by far, are within the vicinity of Anderson Dam. The other two locations are Kirby Canyon and near Llagas Avenue north of Morgan Hill.

Habitat: Serpentine soils and dry slopes in chaparral, grassland, and coastal scrub habitats. This shrub species may require fire for the successful germination of seedlings.

Unique Facts: There are only four known populations of Coyote Ceanothus in the world and they all occur in Santa Clara County within four miles of one another on the southern part of Coyote Ridge.

Status: Federal Threatened

Threats: Documented threats to Coyote Ceanothus include residential development, illegal trash dumping, recreation, landfill activities, lack of natural recruitment, altered fire regimes, and possibly grazing.

Conservation Legacy: The documented habitat requirements of Coyote Ceanothus suggest that it should be more widespread than it is. The species’ habitat requirements may be highly specialized, or other factors are preventing its spread into suitable areas. A current survey of known population conditions is necessary. However, all four known populations occur on private land, making surveys difficult.

SANTA CLARA VALLEY DUDLEYA
(Dudleya setchellii)

2005 Janell Hillman

Species Group: Plants

Range: Santa Clara Valley dudleya is only found in Santa Clara County in the vicinity of Coyote Valley, from San Jose south about 20 miles to San Martin.

Habitat: Restricted to rocky outcrops with crevices enough soil to retain moisture and that are deep enough for this species’ roots, which are at least 6 inches long. Outcrops must also be surrounded by serpentine grassland and oak woodland.

Unique Facts: This species was first discovered on Tulare Hill, just south of the City of San Jose, in 1901. Santa Clara County is the only place in the world that it is known to occur. This species and many of its relatives have fleshy leaves that store water during the long summer drought.

Status: Federal Endangered

Threats: The primary threats to Santa Clara Valley Dudleya are overgrazing, development, and competition from non-native species. Over-collecting is also a significant threat to Santa Clara Valley Dudleya, because of its attractiveness. Other threats include feral pigs, off-road vehicle use, and foot traffic.

Conservation Legacy: The minimal number of suitable habitats greatly limit the species distribution of the Santa Clara Valley Dudleya. Of the 37 known occurrences within the study area, 17 are located on private land, 13 on public land, and five on land of unknown ownership. The remaining two occurrences are located partially on private land and partially on public land. Two of the populations on private land are located on land owned by IBM, who plans to preserve them.

Recovery of Santa Clara Valley Dudleya will require protection and management of extant populations, educational outreach in the San Jose area, as well as seed collection and banking.

METCALF CANYON JEWELFLOWER
(Streptanthus albidus ssp. albidus)

Species Group: Plants

Range: Highly restricted current and historic range; found only within Santa Clara County in the 20 miles from San Jose south to Anderson Reservoir.

Habitat: Serpentine grasslands and on serpentine outcrops and road cuts that have little soil development and are surrounded by grasslands.

Unique Facts: Appropriately named, this subspecies was originally discovered in Metcalf Canyon just south of San Jose, California. Like many serpentine grassland plants, this subspecies may benefit from fires that keep invasive grasses in check.

Status: Federal Endangered

Threats: Urban development and cattle grazing pose the greatest threats to Metcalf Canyon Jewelflower, from impacts such as construction activities, human disturbance, habitat fragmentation, and/or a decline in the soil seed bank. Populations of plants located on steep road cuts or large rock outcrops are less accessible to development and cattle, and are therefore more likely to survive.

Potentially vulnerable populations in the Santa Clara Valley Habitat Plan project area include one site located next to an active quarry and one site near an active landfill. Road construction through serpentine areas may create habitat for Metcalf Canyon Jewelflower by exposing serpentine rock that can be colonized. However, road maintenance and construction can also impact populations which have developed or occur on or near road cuts and along roads.

Conservation Legacy: Very little is known about the life history stages and reproductive biology of Metcalf Canyon Jewelflower, therefore all populations are important to protect. Potential ecoregion subsections of suitable habitat include the Fremont-Livermore Hills and Valleys, Leeward Hills, Western Diablo Range, and Diablo Range.

BAY CHECKERSPOT BUTTERFLY
(Euphydryas editha bayensis)

Species Group: Invertebrates

Range: Found on the San Francisco peninsula, and San Mateo and Santa Clara Counties

Habitat: Bay Area hillsides.  Shallow, serpentine-derived or similar soils in association with its primary host plants, California plantain and purple owl's clover.

Unique Fact: Has several rows of colorful orange, red, white and black spots upon its wings. The bay checkerspot is unique to the Bay Area and depends on native plants such as the California plantain and purple owl’s clover for survival.

Status: Federal Threatened

Article: The Checkerspot Mystery