Bay Checkerspot
Encyclopedia
--173.79.54.79 21:10, 1 December 2011 (UTC)
The Bay Checkerspot (Euphydryas editha bayensis) is a threatened
insect
subspecies which is native to the U.S. State of . Since the 23911s the population of checkerspots
has been in serious decline. Because this particular subspecies is so well studied, the decline was quickly recognized leading to its federally threatened status relatively quickly in 1987. Recently, two authors have advocated a reclassification for this subspecies of the checkerspot common to western North America, Euphydryas editha. The classification, to Euphydryas editha editha, is for reasons of historical precedence ; however, this has not been accepted by the scientific community.
the checkerspot is part of a group of brush-footed butterflies. The insect's forewings are marked with black bands along the veins of the wing's upper surface. The bands contrast sharply with bright red, yellow and white spots. The Bay Checkerspot differs from other checkerspots. From the LuEsther's Checkerspot (E. editha luestherae) by being darker, it also lacks the relatively uninterrupted red band on the outer wing which the LuEsther's Checkerspot has. It is not as dark and brighter red and yellow than the Island Checkerspot (E. editha insularis), which lives on the Channel Islands
and nearby mainland. It is the black banding that gives the Bay Checkerspot its unique appearance and its name. The bands give the Bay Checkerspot a much more checkered appearance than other subspecies such as the Quino Checkerspot
(E. editha quino) or the Mono Checkerspot (E. editha monoensis).
The eggs are usually laid in March and April. The adult female will lay up to five masses of eggs which contain 2 to 250 eggs each. The eggs are deposited at the base of the dwarf plantain plant or less frequently the owl's clover or paintbrush. The eggs take about ten days to hatch and upon emergence from the eggs the larva
e grow for a period of two weeks or more during which they shed their skin until they reach their 4th instare. Any larvae that successfully enters the fourth instare enter a period of diapause that lasts through the entire summer. During diapause they spend time under rocks or within cracks in the soil. When the diapause
ends they resume activity, feeding and move to complete their development into adult Bay checkerspot butterflies.
is dramatically affected by nectar availability.
, exotic non-natives that naturalize in the area, are two of the three most grave threats to this and several other species of butterfly. The threat to the butterfly that is likely greatest comes from the increasing emission of nitrogen
in California.
. Most of the San Francisco peninsula, mountains near San Jose
, Oakland Hills
and several locales around Alameda County were once home to populations of the butterfly. Areas east, west and south of the bay, from Twin Peaks
to Mount Diablo in Contra Costa County, all the way south to Hollister
, the butterfly occurred. Many of these areas no longer support the subspecies as development of the area increased throughout the 20th century. Today the only populations known inhabit areas of Santa Clara
County. Disturbances, specifically the altered regimes of these disturbances (i.e. lack of fire) have, along with invasive grassland plants, induced decline in the population of the host plants.
The current range is much reduced and patchy at that. Of all occurrences of the butterfly known when the subspecies was listed as threatened in 1987, all in San Mateo County have disappeared. A reintroduction of 1000 larvae to Edgewood Park in February 2007 did not result in a re-establishment of a population at this location. The subspecies was last observed at San Bruno Mountain in 1985 and at Jasper Ridge Biological Preserve in 1998. All remaining known populations of the butterfly are in Santa Clara County. The U.S. Fish and Wildlife Service recommends that any area of appropriate habitat within the historic range should be considered "potentially occupied." One site in Santa Clara County that has a large source population, that may number in the hundreds of thousands, is near the City of Morgan Hill on a ridge line currently called Coyote Ridge.
In the area of Jasper Ridge Biological Preserve local populations were deemed extinct in 1998. The populations of butterflies at Jasper Ridge had been the subject of intensive study and research at the lead of Stanford biologist Paul Ehrlich
. Ehrlich had studied the Jasper Ridge populations since 1960 and researchers were able to examine 70 years of climate data and conclude that gigantic fluctuations in local climate probably hastened the demise of the Jasper Ridge Bay checkerspot populations. Ehrlich contends that prior to Spanish settlement of California the Bay checkerspots were almost certainly ubiquitous in California. It was the inadvertent import of invasive plant species in the hay that settlers fed cattle that brought unnatural competition for the native plants that sustained the Bay checkerspot.
The butterfly and its host plants thrive in areas with serpentine soil
, soils derived from the serpentinite
mineral, and other ultramafic rocks. The habitat has been described as consisting of three general types. Type one is the primary habitat which occurs on native grasslands located upon very large serpentine outcroppings. Type two is secondary or "satellite" habitat "islands" which occur in native grasslands on smaller serpentine outcrops. These satellites are typically generating very robust populations of Bay checkerspots in favorable weather with good habitat conditions. Type three are the tertiary habitats. These areas are where both Bay checkerspot larva and the plants they feed on occur in non serpentine soils with similarities to serpentine derived soil.
The possible reclassification of Euphydryas editha bayensis would indicate a change in range for the Bay checkerspot because of several populations of checkerspot butterflies whose subspecific status has been uncertain. If the nomenclature change was accepted it could represent a range extension for the threatened butterfly.
The Bay checkerspot depends upon plants in two different genera as a larva. The primary host plant is of the genus Plantago
while the secondary host plants occur in the genus Castilleja
.
, or Dwarf Plantain, is one of the primary host plants in the genus Plantago
for the Bay checkerspot Butterfly. In many years, the plantain dries up causing the checkerspot larvae to seek a secondary host plant. P. erecta is native to California and only found in western North America. As the primary host plant for the Bay checkerspot, it is an important species for conservation of the butterfly. P. erecta is known variously as California Plantain, English Plantain, Foothill Plantain, Dotseed Plantain, and Dwarf Plantain. It is typically found in coastal sage scrub, foothill woodland
, and chaparral
biome
s.
Castilleja exserta
is known by a handful of common names: Exserted Indian paintbrush, sometimes Red owl's clover, or Purple Indian paintbrush. It is one of two secondary larval host plants of the butterfly that remains edible later in the season and acts as a back up when the dwarf plantain dries up. The plant can grow up to 16 inches (406.4 mm) in height. It prefers mesas, slopes and open areas in ponderosa pine forests and poppy fields at elevations from 1,500 to 4,500 feet (1,370 m). The flowers bloom from March to May and are about 1.25 inches long and formed in dense spikes, they are a magenta or purple color on the lower corolla lips and have yellow or white tips. The bract
, modified leaves, are a reddish purple and hold 5 to 7 lobes, each about one inch long. It ranges from middle to southern California, into southern Arizona and northern Mexico.
The plant's original classification, Orthocarpus purpurascens, has been shown, after careful study, to have been incorrect. Study showed that it belonged to the lineage of Castilleja
.
. On Sept. 11, 1984 the USFWS proposed that 8,300 acres (34 km²) in five sites be declared "
critical habitat
" for the Bay checkerspot. Areas included San Bruno Mountain
, Edgewood County Park
and its adjacent watershed lands, Redwood City
, between the boundary with Woodside
, Jasper Ridge and Coyote Ridge in the Morgan Hill zone.
The USFWS has identified several of these areas as core habitat areas, which it considers essential to the survival of the subspecies. These areas include some of those mentioned above and others. Areas along the Coyote Ridge, including Kirby, Metcalf, San Felipe, Silver Creek Hills have been designated "core habitat areas." An area of 1,100 acres (4 km²) in the Santa Teresa Hills
has been labeled a "potential core area" by the Wildlife Service. The Service also denotes some other areas, near core populations, of good quality, meaning suitable habitat. Tulare Hill is one of those areas and along with the Santa Teresa Hills and Redwood City, is considered a "stepping stone."
through air pollution. Increased nitrogen increases the fertility of serpentine soil
s, soils naturally low in nitrogen. This increased fertility allows invasive plants to thrive and exclude the nectar sources that the Bay checkerspot needs. This is where moderate grazing brings help to the threatened checkerspot. In a large metapopulation south of San Jose, removal of cattle from grassland
s that the butterfly inhabitated led to a significant decrease in the butterfly population because grazing leads to a net export of nitrogen as the cattle are removed for slaughter after eating the plants of the grasslands. In this way, moderate grazing enhances the butterfly's chance for survival.
Increasing nitrogen emission is a problem facing the delicate balance within the ecosystems that contain the Bay checkerspot in many areas. At Coyote Ridge the problem is well documented by conservation biologist Stuart Weiss. Faced with a declining population of Bay checkerspots at Coyote Ridge, Weiss searched for a cause. He found a link to a combination of pollution from the freeway below the ridge and, again, a cutback in cattle grazing locally. Weiss documented how nitrogen oxide
emissions from cars enriched the nutrient-poor serpentine soil. This is a prime example of the nitrogen effect explained above. Aside from helping decrease nitrogen, the cattle also help to control invasive grasses by eating them. Any question about whether nitrogen emissions from cars traversing U.S. Route 101
, 110,000 vehicles daily, is significant evaporates when faced with monitoring statistics from Weiss. His monitoring equipment has confirmed that 15 to 20 pounds of nitrogen per acre is deposited on Coyote Ridge annually. Some of the particles stick to the plant and ground and are washed into the soil, and others are directly absorbed by the plants themselves. By contrast, pollution from power plants and vehicles drops only about four to five pounds of nitrogen per acre per year on the Jasper Ridge preserve.
was once home to a population of the threatened checkerspot. That population went extinct in 1998. Ehrlich and his colleagues accumulated a mass of data about the fluctuations of the Bay checkerspot populations at Jasper Ridge than probably any other invertebrate known. Consequently, Stanford University has dispatched Ehrlich and others to conduct "longterm studies of the Bay checkerspot butterfly and feasibility of reintroduction. The professors participating, one each from biology, history, soil science and law, are examining the issues in restoring any extinct species or lost habitat. The goal of this study is to help determine whether and how to attempt a reintroduction of Bay checkerspots to Jasper Ridge.
Other goals of the Jasper Ridge study include analyzing the regulatory framework for endangered species and how changes might aid recovery of species, characterizing the genetics of research collections and possible donor populations and examining the historical changes in ownership, management and condition of the serpentine grasslands that the Bay checkerspot calls home.
The region known as Coyote Ridge refers to an unnamed ridge in Santa Clara County. A variety of names have been applied to areas along the ridge where known populations of Bay checkerspots have or do currently live. Some of these names include, Morgan Hill, Kirby Canyon, East Coyote Foothills and, of course, Coyote Ridge. The U.S. Fish and Wildlife Service identified four core areas along Coyote Ridge that require attention as Bay checkerspot habitat. They have termed them Kirby, Metcalf, San Felipe and Silver Creek Hills.
Right before the Bay checkerspot was federally listed the USFWS entered into an agreement with Waste Management of California, Inc. and also the city of San Jose. The agreement was made under provisions of the Endangered Species Act, specifically section 7.a.4. The agreement provided for the minimization and compensation for any take of Bay checkerspots due to any construction and operations at Kirby landfill in Kirby Canyon, along Coyote Ridge. The landfill is located adjacent to the large Kirby population of Bay checkerspots. Key aspects of the agreement include:
Projects at Kirby Canyon were behind the original schedule in the late 1990s. Revegetation efforts were slowed in large part due to lower than expected rates landfill filling. Waste Management fulfilled the ten year duration of the agreement and offered after to fund 50 percent of the agreement for three additional years.
Metcalf has been designated a "Critical Habitat" area by a 2001 USFWS rule change. The area, known in the rule as the Metcalf Unit, includes 3,351 acres (14 km²) of Santa Clara County
. The habitat contains the Metcalf area for Bay checkerspot which one of the four largest habitat areas and three largest current populations of Bay Checkerspot. As of spring 2000 the area supported the densest population of Bay checkerspots known. With hundreds of acres of serpentine soils, thousands of Bay Checkerspot butterflies occur within the unit, which is considered one of the centers of the subspecies' metapopulation in Santa Clara County. The USFWS Recovery Plan for Serpentine Soils Species put a high priority for conservation of the butterfly and its habitat. Metcalf is adjacent to Kirby to south and San Felipe to east, Silver Creek Hills is to the north and the Tulare Hill Corridor is to the west. This connectivity is crucial for Bay checkerspot dispersal throughout the Coyote Ridge area. The land in the Metcalf area is widely distributed amongst various parties. Portions of it lie within the city of San Jose and on private lands in unincorporated Santa Clara County. Parts of the Santa Clara County Motorcycle Park, Coyote Creek Park and the land of the Santa Clara Valley Water District fall within the Metcalf Unit.
Primarily on private lands, 998 acres (4 km²), of land, termed the San Felipe Unit by USFWS, has been declared "Critical Habitat" for the Bay checkerspot butterfly per a 2001 rule. On the land is the San Felipe population area which is one of the four largest habitat areas and three largest current populations of Bay Checkerspots. The San Felipe area is considered Santa Clara County's metapopulation of the butterfly. The Recovery Plan, from the USFWS, considered the San Felipe area to be of the highest priority for conservation. Though several hundred acres of serpentine soils occur within the unit and include nectaring and dispesal areas there are no public lands in San Felipe.
It was a housing and golf course project that spurred the creation of the Silver Creek Butterfly Conservation Area. The homes were built, about 1,500 of them, and the golf course went in on about 1,500 acres (6 km²) in the Silver Creek Valley, east of San Jose. The project resulted in the loss of about 18.5 acres (74,866.9 m²) of serpentine habitat for the Bay Checkerspot. As compensation the developer, Shea Homes, in 1991, established a permanent 115 acre (0.4653889 km²) site for butterfly conservation in the Silver Creek Hills. The company also provided for ten years of monitoring of the preserve. Shea Homes also deposited $100,000 into an account dedicated to regional conservation of the Bay Checkerspot, money now managed by USFWS.
With the Silver Creek Butterfly Conservation Area up and running the area population of Bay Checkerspots increased markedly. By 1994 there were tens of thousands of adult butterflies. This population crashed in 1995 and 1996 due to problems implementing necessary management actions. By 1997 no post-diapause
larvae were found and only three adults were observed during annual monitoring. Other populations are located on nearby property in the Silver Creek Hills and the nearby San Felipe habitat area.
The preserve was threatened by a proposed golf course development in 1983. A 1993 resolution helped secure the park's future. That year the San Mateo County Board of Supervisors closed the golf course issue when they adopted a resolution that designated Edgewood Park "a scenic natural area where outstanding features as well as significant wildlife habitats are preserved in their present state for the enjoyment, education and well-being of the public." At the same time the county also modified their agreement with Midpeninsula Open Space District, adding a clause to prohibit golf course development and emphasize natural resource preservation and low intensity recreation. The Bay Checkerspot went locally extinct during the early 2000s, last observed at Edgewood Park in 2002. This local extinction was attributed to nitrogen deposition from cars traveling on adjacent Highway 280, which fertilized invasive Italian ryegrass and choked out native plants required by the butterflies. Subsequently, the habitat was restored by mowing at an appropriate time of year to reduce the Italian ryegrass and allow the native plants to regrow. In early 2007, 1000 Bay Checkerspot larvae were reintroduced to the park.
Habitat Conservation Plan (HCP), the first of its kind in the United States, was adopted in 1983. Currently, it is the only HCP
that potentially addresses the Bay Checkerspot. The plan covers some 3,400 acres (14 km²) in northern San Mateo County and identifies seven animal species and 44 plant species to be conserved. Among them, the federally endangered Mission blue and the Bay Checkerspot butterfly, the Bay Checkerspot was not federally listed when the plan was adopted. Thus, this HCP's primary focus is on the two species of butterfly that were federally listed when it was adopted in 1983, the Mission blue butterfly and San Bruno elfin butterfly
. The permit for the plan expires on March 31, 2013 and there are currently no provisions in the HCP for incidental take
of Bay Checkerspots. The Bay Checkerspot was lost on San Bruno Mountain around 1986. The impetuses included fires, non native plant species and "natural fluctuations. The reintroduction of the Bay Checkerspot is one of the goals of the San Bruno HCP.
The Bay Checkerspot (Euphydryas editha bayensis) is a threatened
Threatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...
insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
subspecies which is native to the U.S. State of . Since the 23911s the population of checkerspots
Euphydryas
Euphydryas is a genus of Nymphalidae butterfly.-Species:Euphydryas species-group:* Euphydryas phaeton – Baltimore CheckerspotHypodryas species-group:...
has been in serious decline. Because this particular subspecies is so well studied, the decline was quickly recognized leading to its federally threatened status relatively quickly in 1987. Recently, two authors have advocated a reclassification for this subspecies of the checkerspot common to western North America, Euphydryas editha. The classification, to Euphydryas editha editha, is for reasons of historical precedence ; however, this has not been accepted by the scientific community.
Appearance
The Bay Checkerspot butterfly is a medium sized butterfly with a wing span of slightly more than 2 inches (50.8 mm). As a member of the family NymphalinaeNymphalinae
Nymphalinae is a subfamily of brush-footed butterflies . Sometimes, the Limenitidinae are included here as further tribe, while the Melitaeini are occasionally considered a distinct subfamily.- Systematics:...
the checkerspot is part of a group of brush-footed butterflies. The insect's forewings are marked with black bands along the veins of the wing's upper surface. The bands contrast sharply with bright red, yellow and white spots. The Bay Checkerspot differs from other checkerspots. From the LuEsther's Checkerspot (E. editha luestherae) by being darker, it also lacks the relatively uninterrupted red band on the outer wing which the LuEsther's Checkerspot has. It is not as dark and brighter red and yellow than the Island Checkerspot (E. editha insularis), which lives on the Channel Islands
Channel Islands of California
The Channel Islands of California are a chain of eight islands located in the Pacific Ocean off the coast of Southern California along the Santa Barbara Channel in the United States of America...
and nearby mainland. It is the black banding that gives the Bay Checkerspot its unique appearance and its name. The bands give the Bay Checkerspot a much more checkered appearance than other subspecies such as the Quino Checkerspot
Quino Checkerspot
The Quino Checkerspot is native to California and Mexico. It is a subspecies of the common Edith's Checkerspot and the second such subspecies to be listed under the federal Endangered Species Act. This species, like many others, has undergone several changes in nomenclature and classification...
(E. editha quino) or the Mono Checkerspot (E. editha monoensis).
Life cycle
Adult butterflies emerge in early spring. The adults, which live an average of ten days emerge during a six week period from late February to early May. The male Bay checkerspot typically emerges four to eight days before the female. The males have one goal, reproduction. They find and mate with a female immediately upon emerging. The male mates many times while most females mate only once during the flight season. Besides mating the adults spend time foraging for nectar and for the females, laying eggs.The eggs are usually laid in March and April. The adult female will lay up to five masses of eggs which contain 2 to 250 eggs each. The eggs are deposited at the base of the dwarf plantain plant or less frequently the owl's clover or paintbrush. The eggs take about ten days to hatch and upon emergence from the eggs the larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e grow for a period of two weeks or more during which they shed their skin until they reach their 4th instare. Any larvae that successfully enters the fourth instare enter a period of diapause that lasts through the entire summer. During diapause they spend time under rocks or within cracks in the soil. When the diapause
Diapause
Diapause is the delay in development in response to regularly and recurring periods of adverse environmental conditions. It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions...
ends they resume activity, feeding and move to complete their development into adult Bay checkerspot butterflies.
Diet
While the larvae are dependent on the host plants, mostly the dwarf plantain, for sustenance the adult butterflies live on nectar. They feed on a variety of plants associated with serpentine grasslands. Some of these plants include California goldfields, White turtlehead, Desert parsley, scytheleaf onion, false babystars, intermediate fiddleneck and others. Female fecundityFecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
is dramatically affected by nectar availability.
Habitat
This subspecies of butterfly faces declining habitat which has contributed to its migration onto the list of federally threatened species. Like other endangered and threatened species of butterfly in and around the Bay Area the checkerspot is faced with rapid human development of areas once considered prime habitat. Development and the proliferation of invasive speciesInvasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
, exotic non-natives that naturalize in the area, are two of the three most grave threats to this and several other species of butterfly. The threat to the butterfly that is likely greatest comes from the increasing emission of nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
in California.
Range
The historic range of the checkerspot included many areas around the San Francisco BaySan Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
. Most of the San Francisco peninsula, mountains near San Jose
San Jose, California
San Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
, Oakland Hills
Oakland Hills, Oakland, California
Oakland Hills is an informal term used to indicate the city neighborhoods lying within the eastern portion of Oakland, California.-The geologic feature:...
and several locales around Alameda County were once home to populations of the butterfly. Areas east, west and south of the bay, from Twin Peaks
Twin Peaks, San Francisco, California
The Twin Peaks are two hills with an elevation of about near the geographic center of San Francisco, California. Except for Mount Davidson, they are the highest points in the city.-Location and climate:...
to Mount Diablo in Contra Costa County, all the way south to Hollister
Hollister, California
Hollister is a city in and the county seat of San Benito County, California, United States. The population was 34,928 at the 2010 census. Hollister is primarily an agricultural town.-History:...
, the butterfly occurred. Many of these areas no longer support the subspecies as development of the area increased throughout the 20th century. Today the only populations known inhabit areas of Santa Clara
Santa Clara County, California
Santa Clara County is a county located at the southern end of the San Francisco Bay Area in the U.S. state of California. As of 2010 it had a population of 1,781,642. The county seat is San Jose. The highly urbanized Santa Clara Valley within Santa Clara County is also known as Silicon Valley...
County. Disturbances, specifically the altered regimes of these disturbances (i.e. lack of fire) have, along with invasive grassland plants, induced decline in the population of the host plants.
The current range is much reduced and patchy at that. Of all occurrences of the butterfly known when the subspecies was listed as threatened in 1987, all in San Mateo County have disappeared. A reintroduction of 1000 larvae to Edgewood Park in February 2007 did not result in a re-establishment of a population at this location. The subspecies was last observed at San Bruno Mountain in 1985 and at Jasper Ridge Biological Preserve in 1998. All remaining known populations of the butterfly are in Santa Clara County. The U.S. Fish and Wildlife Service recommends that any area of appropriate habitat within the historic range should be considered "potentially occupied." One site in Santa Clara County that has a large source population, that may number in the hundreds of thousands, is near the City of Morgan Hill on a ridge line currently called Coyote Ridge.
In the area of Jasper Ridge Biological Preserve local populations were deemed extinct in 1998. The populations of butterflies at Jasper Ridge had been the subject of intensive study and research at the lead of Stanford biologist Paul Ehrlich
Paul R. Ehrlich
Paul Ralph Ehrlich is an American biologist and educator who is the Bing Professor of Population Studies in the department of Biological Sciences at Stanford University and president of Stanford's Center for Conservation Biology. By training he is an entomologist specializing in Lepidoptera , but...
. Ehrlich had studied the Jasper Ridge populations since 1960 and researchers were able to examine 70 years of climate data and conclude that gigantic fluctuations in local climate probably hastened the demise of the Jasper Ridge Bay checkerspot populations. Ehrlich contends that prior to Spanish settlement of California the Bay checkerspots were almost certainly ubiquitous in California. It was the inadvertent import of invasive plant species in the hay that settlers fed cattle that brought unnatural competition for the native plants that sustained the Bay checkerspot.
The butterfly and its host plants thrive in areas with 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....
, soils derived from the serpentinite
Serpentinite
Serpentinite is a rock composed of one or more serpentine group minerals. Minerals in this group are formed by serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle...
mineral, and other ultramafic rocks. The habitat has been described as consisting of three general types. Type one is the primary habitat which occurs on native grasslands located upon very large serpentine outcroppings. Type two is secondary or "satellite" habitat "islands" which occur in native grasslands on smaller serpentine outcrops. These satellites are typically generating very robust populations of Bay checkerspots in favorable weather with good habitat conditions. Type three are the tertiary habitats. These areas are where both Bay checkerspot larva and the plants they feed on occur in non serpentine soils with similarities to serpentine derived soil.
The possible reclassification of Euphydryas editha bayensis would indicate a change in range for the Bay checkerspot because of several populations of checkerspot butterflies whose subspecific status has been uncertain. If the nomenclature change was accepted it could represent a range extension for the threatened butterfly.
Host plants
Plantago
Plantago is a genus of about 200 species of small, inconspicuous plants commonly called plantains. They share this name with the very dissimilar plantain, a kind of banana. Most are herbaceous plants, though a few are subshrubs growing to 60 cm tall. The leaves are sessile, but have a narrow...
while the secondary host plants occur in the genus Castilleja
Castilleja
Castilleja, commonly known as Indian paintbrush or Prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one species as far west as the Kola Peninsula in Siberia...
.
Plantago erecta
Plantago erectaPlantago erecta
Plantago erecta is a small, unassuming annual herb with needle-like leaves and translucent flowers clustered on a stalk. It grows in sandy, clay, or serpentine soils, on grassy slopes and flats or open woodland, from California to Oregon...
, or Dwarf Plantain, is one of the primary host plants in the genus Plantago
Plantago
Plantago is a genus of about 200 species of small, inconspicuous plants commonly called plantains. They share this name with the very dissimilar plantain, a kind of banana. Most are herbaceous plants, though a few are subshrubs growing to 60 cm tall. The leaves are sessile, but have a narrow...
for the Bay checkerspot Butterfly. In many years, the plantain dries up causing the checkerspot larvae to seek a secondary host plant. P. erecta is native to California and only found in western North America. As the primary host plant for the Bay checkerspot, it is an important species for conservation of the butterfly. P. erecta is known variously as California Plantain, English Plantain, Foothill Plantain, Dotseed Plantain, and Dwarf Plantain. It is typically found in coastal sage scrub, foothill woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
, and chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
s.
Castilleja exserta
Castilleja exserta
Castilleja exserta is a species of plant in the genus which includes the Indian paintbrushes. Its common names include purple owl's clover, escobita, and exserted Indian paintbrush....
is known by a handful of common names: Exserted Indian paintbrush, sometimes Red owl's clover, or Purple Indian paintbrush. It is one of two secondary larval host plants of the butterfly that remains edible later in the season and acts as a back up when the dwarf plantain dries up. The plant can grow up to 16 inches (406.4 mm) in height. It prefers mesas, slopes and open areas in ponderosa pine forests and poppy fields at elevations from 1,500 to 4,500 feet (1,370 m). The flowers bloom from March to May and are about 1.25 inches long and formed in dense spikes, they are a magenta or purple color on the lower corolla lips and have yellow or white tips. The bract
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
, modified leaves, are a reddish purple and hold 5 to 7 lobes, each about one inch long. It ranges from middle to southern California, into southern Arizona and northern Mexico.
The plant's original classification, Orthocarpus purpurascens, has been shown, after careful study, to have been incorrect. Study showed that it belonged to the lineage of Castilleja
Castilleja
Castilleja, commonly known as Indian paintbrush or Prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one species as far west as the Kola Peninsula in Siberia...
.
Castilleja densiflora
C. densiflora, commonly referred to as purple owl's clover is the second of two secondary larval host plants of the butterfly. Similar to C. exersta, it often remains green later into the spring than the butterfly's primary host plant. The plant is generally between 4 and 12 inches (304.8 mm) in height and grows in small colonies. Flowers can be observed between April and July. Flowers are pink/purple to white/yellow with five petals with white lobes that form a yellow "beak" and "eye spots" on the lower lip, which resembles the face of an owl. The species can be found in a variety of habitats including: Foothill Woodland, Mixed Evergreen Forest, Northern Coastal Scrub, Chaparral, Foothill Woodland, Yellow Pine Forestis, and native grasslands.Habitat conservation
The Bay checkerspot butterfly is the subject of a number of conservation programs, both private and public. Some of the more notable projects are headed by the U.S. Fish and Wildlife Service (USFWS) and Stanford UniversityStanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
. On Sept. 11, 1984 the USFWS proposed that 8,300 acres (34 km²) in five sites be declared "
critical habitat
Critical habitat
Critical habitat is a habitat area essential to the conservation of a listed species, though the area need not actually be occupied by the species at the time it is designated. This is a specific term and designation within the U.S...
" for the Bay checkerspot. Areas included San Bruno Mountain
San Bruno Mountain
San Bruno Mountain in northern San Mateo County, California is the northernmost part of the Santa Cruz Mountains. Most of the mountain lies within the San Bruno Mountain State Park, a unique open-space island in the midst of the San Francisco Peninsula's urbanization. Next to the state park is the...
, Edgewood County Park
Edgewood County Park
Edgewood County Park and Natural Preserve is a 467-acre protected area located in San Mateo County, San Francisco, United States, and is best known for its spring wildflower displays...
and its adjacent watershed lands, Redwood City
Redwood City, California
Redwood City is a California charter city located on the San Francisco Peninsula in Northern California, approximately 27 miles south of San Francisco, and 24 miles north of San Jose. Redwood City's history spans from its earliest inhabitation by the Ohlone people, to its tradition as a port for...
, between the boundary with Woodside
Woodside, California
Woodside is a small incorporated town in San Mateo County, California, United States, on the San Francisco Peninsula. It uses a council-manager system of government. The U.S. Census estimated the population of the town to be 5,287 in 2010....
, Jasper Ridge and Coyote Ridge in the Morgan Hill zone.
The USFWS has identified several of these areas as core habitat areas, which it considers essential to the survival of the subspecies. These areas include some of those mentioned above and others. Areas along the Coyote Ridge, including Kirby, Metcalf, San Felipe, Silver Creek Hills have been designated "core habitat areas." An area of 1,100 acres (4 km²) in the Santa Teresa Hills
Santa Teresa Hills
The Santa Teresa Hills are a mountain range in Santa Clara County, California, located partly in the city of San Jose. They are one the landforms around the Almaden Valley.-Rancho San Vicente:...
has been labeled a "potential core area" by the Wildlife Service. The Service also denotes some other areas, near core populations, of good quality, meaning suitable habitat. Tulare Hill is one of those areas and along with the Santa Teresa Hills and Redwood City, is considered a "stepping stone."
Nitrogen effect
One of the interesting dynamics of conservation of this butterfly is associated with increased nitrogenNitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
through air pollution. Increased nitrogen increases the fertility of 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, soils naturally low in nitrogen. This increased fertility allows invasive plants to thrive and exclude the nectar sources that the Bay checkerspot needs. This is where moderate grazing brings help to the threatened checkerspot. In a large metapopulation south of San Jose, removal of cattle from grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...
s that the butterfly inhabitated led to a significant decrease in the butterfly population because grazing leads to a net export of nitrogen as the cattle are removed for slaughter after eating the plants of the grasslands. In this way, moderate grazing enhances the butterfly's chance for survival.
Increasing nitrogen emission is a problem facing the delicate balance within the ecosystems that contain the Bay checkerspot in many areas. At Coyote Ridge the problem is well documented by conservation biologist Stuart Weiss. Faced with a declining population of Bay checkerspots at Coyote Ridge, Weiss searched for a cause. He found a link to a combination of pollution from the freeway below the ridge and, again, a cutback in cattle grazing locally. Weiss documented how nitrogen oxide
Nitrogen oxide
Nitrogen oxide can refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:* Nitric oxide, also known as nitrogen monoxide, , nitrogen oxide* Nitrogen dioxide , nitrogen oxide...
emissions from cars enriched the nutrient-poor serpentine soil. This is a prime example of the nitrogen effect explained above. Aside from helping decrease nitrogen, the cattle also help to control invasive grasses by eating them. Any question about whether nitrogen emissions from cars traversing U.S. Route 101
U.S. Route 101
U.S. Route 101, or U.S. Highway 101, is an important north–south U.S. highway that runs through the states of California, Oregon, and Washington, on the West Coast of the United States...
, 110,000 vehicles daily, is significant evaporates when faced with monitoring statistics from Weiss. His monitoring equipment has confirmed that 15 to 20 pounds of nitrogen per acre is deposited on Coyote Ridge annually. Some of the particles stick to the plant and ground and are washed into the soil, and others are directly absorbed by the plants themselves. By contrast, pollution from power plants and vehicles drops only about four to five pounds of nitrogen per acre per year on the Jasper Ridge preserve.
Jasper Ridge
Jasper Ridge Biological PreserveJasper Ridge Biological Preserve
The Jasper Ridge Biological Preserve is a 1,200 acre is a nature preserve and biological field station owned by Stanford University, located at south of Sand Hill Road and west of Interstate 280 in Portola Valley, California. It is used by students, researchers, and docents to conduct biology...
was once home to a population of the threatened checkerspot. That population went extinct in 1998. Ehrlich and his colleagues accumulated a mass of data about the fluctuations of the Bay checkerspot populations at Jasper Ridge than probably any other invertebrate known. Consequently, Stanford University has dispatched Ehrlich and others to conduct "longterm studies of the Bay checkerspot butterfly and feasibility of reintroduction. The professors participating, one each from biology, history, soil science and law, are examining the issues in restoring any extinct species or lost habitat. The goal of this study is to help determine whether and how to attempt a reintroduction of Bay checkerspots to Jasper Ridge.
Other goals of the Jasper Ridge study include analyzing the regulatory framework for endangered species and how changes might aid recovery of species, characterizing the genetics of research collections and possible donor populations and examining the historical changes in ownership, management and condition of the serpentine grasslands that the Bay checkerspot calls home.
Coyote Ridge
Kirby
Right before the Bay checkerspot was federally listed the USFWS entered into an agreement with Waste Management of California, Inc. and also the city of San Jose. The agreement was made under provisions of the Endangered Species Act, specifically section 7.a.4. The agreement provided for the minimization and compensation for any take of Bay checkerspots due to any construction and operations at Kirby landfill in Kirby Canyon, along Coyote Ridge. The landfill is located adjacent to the large Kirby population of Bay checkerspots. Key aspects of the agreement include:
- limited impacts to total area, with impacts concentrated in lower quality habitat
- phased landfill use
- restoration of filled areas with appropriate vegetation
- a 15-year lease of 267 acres (1.1 km²) of high quality habitat for Bay Checkerspot conservation
- restoration and management of other Bay checkerspot habitat
- monitoring of Bay checkerspot habitat and populations
- possible acquisition of Bay checkerspot habitat for further protection
- establishment of a trust fund to finance the agreement
Projects at Kirby Canyon were behind the original schedule in the late 1990s. Revegetation efforts were slowed in large part due to lower than expected rates landfill filling. Waste Management fulfilled the ten year duration of the agreement and offered after to fund 50 percent of the agreement for three additional years.
Metcalf
Metcalf has been designated a "Critical Habitat" area by a 2001 USFWS rule change. The area, known in the rule as the Metcalf Unit, includes 3,351 acres (14 km²) of Santa Clara County
Santa Clara County, California
Santa Clara County is a county located at the southern end of the San Francisco Bay Area in the U.S. state of California. As of 2010 it had a population of 1,781,642. The county seat is San Jose. The highly urbanized Santa Clara Valley within Santa Clara County is also known as Silicon Valley...
. The habitat contains the Metcalf area for Bay checkerspot which one of the four largest habitat areas and three largest current populations of Bay Checkerspot. As of spring 2000 the area supported the densest population of Bay checkerspots known. With hundreds of acres of serpentine soils, thousands of Bay Checkerspot butterflies occur within the unit, which is considered one of the centers of the subspecies' metapopulation in Santa Clara County. The USFWS Recovery Plan for Serpentine Soils Species put a high priority for conservation of the butterfly and its habitat. Metcalf is adjacent to Kirby to south and San Felipe to east, Silver Creek Hills is to the north and the Tulare Hill Corridor is to the west. This connectivity is crucial for Bay checkerspot dispersal throughout the Coyote Ridge area. The land in the Metcalf area is widely distributed amongst various parties. Portions of it lie within the city of San Jose and on private lands in unincorporated Santa Clara County. Parts of the Santa Clara County Motorcycle Park, Coyote Creek Park and the land of the Santa Clara Valley Water District fall within the Metcalf Unit.
San Felipe
Primarily on private lands, 998 acres (4 km²), of land, termed the San Felipe Unit by USFWS, has been declared "Critical Habitat" for the Bay checkerspot butterfly per a 2001 rule. On the land is the San Felipe population area which is one of the four largest habitat areas and three largest current populations of Bay Checkerspots. The San Felipe area is considered Santa Clara County's metapopulation of the butterfly. The Recovery Plan, from the USFWS, considered the San Felipe area to be of the highest priority for conservation. Though several hundred acres of serpentine soils occur within the unit and include nectaring and dispesal areas there are no public lands in San Felipe.
Silver Creek
With the Silver Creek Butterfly Conservation Area up and running the area population of Bay Checkerspots increased markedly. By 1994 there were tens of thousands of adult butterflies. This population crashed in 1995 and 1996 due to problems implementing necessary management actions. By 1997 no post-diapause
Diapause
Diapause is the delay in development in response to regularly and recurring periods of adverse environmental conditions. It is considered to be a physiological state of dormancy with very specific initiating and inhibiting conditions...
larvae were found and only three adults were observed during annual monitoring. Other populations are located on nearby property in the Silver Creek Hills and the nearby San Felipe habitat area.
Edgewood Park and Natural Preserve
Edgewood Park is located in San Mateo County, California, and provides a small habitat for the Bay Checkerspot, one of the few remaining in the state, it is scattered and isolated like much of the remaining serpentine soil habitat areas left for the Bay Checkerspot. The park is a 467 acre (1.9 km²) woodland and grassland preserve located off of Interstate 280. The preserve has hiking opportunities throughout its serpentine grasslands.The preserve was threatened by a proposed golf course development in 1983. A 1993 resolution helped secure the park's future. That year the San Mateo County Board of Supervisors closed the golf course issue when they adopted a resolution that designated Edgewood Park "a scenic natural area where outstanding features as well as significant wildlife habitats are preserved in their present state for the enjoyment, education and well-being of the public." At the same time the county also modified their agreement with Midpeninsula Open Space District, adding a clause to prohibit golf course development and emphasize natural resource preservation and low intensity recreation. The Bay Checkerspot went locally extinct during the early 2000s, last observed at Edgewood Park in 2002. This local extinction was attributed to nitrogen deposition from cars traveling on adjacent Highway 280, which fertilized invasive Italian ryegrass and choked out native plants required by the butterflies. Subsequently, the habitat was restored by mowing at an appropriate time of year to reduce the Italian ryegrass and allow the native plants to regrow. In early 2007, 1000 Bay Checkerspot larvae were reintroduced to the park.
San Bruno Mountain
The San Bruno MountainSan Bruno Mountain
San Bruno Mountain in northern San Mateo County, California is the northernmost part of the Santa Cruz Mountains. Most of the mountain lies within the San Bruno Mountain State Park, a unique open-space island in the midst of the San Francisco Peninsula's urbanization. Next to the state park is the...
Habitat Conservation Plan (HCP), the first of its kind in the United States, was adopted in 1983. Currently, it is the only HCP
Habitat Conservation Plan
A Habitat conservation plan is a plan prepared under the Endangered Species Act by nonfederal parties wishing to obtain permits for incidental taking of threatened and endangered species....
that potentially addresses the Bay Checkerspot. The plan covers some 3,400 acres (14 km²) in northern San Mateo County and identifies seven animal species and 44 plant species to be conserved. Among them, the federally endangered Mission blue and the Bay Checkerspot butterfly, the Bay Checkerspot was not federally listed when the plan was adopted. Thus, this HCP's primary focus is on the two species of butterfly that were federally listed when it was adopted in 1983, the Mission blue butterfly and San Bruno elfin butterfly
San Bruno elfin butterfly
The San Bruno elfin butterfly is a U.S. Federally listed endangered subspecies which inhabits rocky outcrops and cliffs in coastal scrub on the San Francisco peninsula, endemic to this habitat in California...
. The permit for the plan expires on March 31, 2013 and there are currently no provisions in the HCP for incidental take
Incidental Take Permit
An incidental take permit is a permit issued under Section 10 of the Federal Endangered Species Act to private, non-federal entities undertaking otherwise lawful projects that might result in the take of an endangered or threatened species...
of Bay Checkerspots. The Bay Checkerspot was lost on San Bruno Mountain around 1986. The impetuses included fires, non native plant species and "natural fluctuations. The reintroduction of the Bay Checkerspot is one of the goals of the San Bruno HCP.
Conservation
- Bay Checkerspot Butterfly, Butterfly Conservation Initiative.
- Friends of Edgewood, Friends of Edgewood Natural Preserve
- Edgewood Park & Natural Preserve, San Mateo County.
Government resources
- Federal Rule regarding Critical Habitat, (PDF), 41 pages, Federal Register, April 30, 2001.
News/media
- Critical habitat now includes 23,903 acres within two counties, San Francisco Chronicle, Eric Brazil, May 2, 2001.
- San Bruno's mounting challenge, San Francisco Chronicle, Paul McHugh, Sept. 19, 2002.
Journals
- Climate change hastens extinction, (PDF), 5 pages, PNAS.org, Paul Ehrlich, March 6, 2002.