Range
P. i. missionensis is federally endangered and found in only a few locations. Its habitat is restricted to the San Francisco Bay Area, specifically six areas, the Twin Peaks area in San Francisco County, Fort Baker, a former military installation managed by the National Park Service (NPS), in Marin County, the San Bruno Mountain area in San Mateo County, the Marin Headlands, in Golden Gate National Recreation Area (another NPS entity), Laurelwood Park & Sugarloaf Open Space in the city of San Mateo, and Skyline Ridge, also in San Mateo County. San Bruno Mountain hosts the largest population of Mission Blues, a butterfly that is commonly found around elevations of 700 feet. The coastal scrubland and grassland the Mission Blue requires is found only in and around the Golden Gate of San Francisco. The butterfly depends solely on three species of perennial lupine for its reproduction, the varied lupine, silver lupine and the Summer lupine. The Mission Blue requires the lupine to lay their eggs and nourish the larvae. Without these species, the Mission Blue cannot reproduce and thus cannot survive. Thus, the Mission Blue's habitat parallels that of the lupine species.
Two of the areas inhabited by the Mission Blue are within the confines of the Golden Gate National Recreation Area. Golden Gate staff are working to ease the invasive species problem that has helped reduce the Mission Blue to the endangered species list. They work to remove non-native plants and replant the area with lupine seed along with continual monitoring of the butterfly and its host plant.
Much of the area that the Mission Blue once inhabited has been destroyed. The coastal sage and chaparral and the native grassland habitats have seen unnatural human development in much of the region. The San Mateo County town of Brisbane lies in what may once have been the prime habitat for the butterfly. Near Brisbane, an industrial park and rock quarry have proved damaging to the Mission Blue habitat. Generally, the most negative impactor on Mission Blue habitat is that of residential and industrial development. Aside from development, other human activities have negatively impacted the butterfly's habitat. Those activities include cultivation and grazing as well as the oft human assisted abundance of invasive exotic species. Some of the more impactful exotics include the European gorse and pampas grass. In the Golden Gate Recreation Area, thoroughwort is a particular invasive species which is taking over habitat once occupied by the Mission Blue's lifeblood, the three species of lupine. Of the threats facing the Mission Blue, habitat loss due to human intervention and exotic, invasive species are the two most critical.
Residential and industrial development continually threaten Mission Blue habitat, such as the 1997-2001 seismic retrofitting of the Golden Gate Bridge. Despite costing an additional US$1.2 million to comply to environmental standards the construction project still claimed about 1,500 square metres of butterfly habitat through "incidental take," an exception provided under California law. Through a type of habitat conservation popular since a 1983 amendment to the Endangered Species Act, the incidental take is offset by off-site mitigation and restoration. In this case, the San Francisco Highway and Transportation District in cooperation with the National Park Service funded a US$450,000 off-site restoration plan. The main aspect of this plan was to establish about 8 ha of Mission Blue habitat in the area of the bridge project.
The Mission Blue was first collected in the Mission District of San Francisco in 1937. Today, there is a small colony on Twin Peaks; the species has also been found in Fort Baker, which is in Marin County. However, the majority of today's Mission Blue colonies are found on San Bruno Mountain. Besides those on the mountain, other colonies have been found in San Mateo County. Those colonies have been located at elevations of 690–1,180 ft. Some colonies have been found in the "fog belt" of the coastal mountain range. The Mission Blue colonies in the area prefer coastal chaparral and coastal grasslands which are the predominate biomes where Mission Blues are found.
Read more about this topic: Mission Blue Butterfly
Famous quotes containing the word range:
“No doubt, the short distance to which you can see in the woods, and the general twilight, would at length react on the inhabitants, and make them savages. The lakes also reveal the mountains, and give ample scope and range to our thought.”
—Henry David Thoreau (1817–1862)
“The variables of quantification, ‘something,’ ‘nothing,’ ‘everything,’ range over our whole ontology, whatever it may be; and we are convicted of a particular ontological presupposition if, and only if, the alleged presuppositum has to be reckoned among the entities over which our variables range in order to render one of our affirmations true.”
—Willard Van Orman Quine (b. 1908)
“We must continually remind students in the classroom that expression of different opinions and dissenting ideas affirms the intellectual process. We should forcefully explain that our role is not to teach them to think as we do but rather to teach them, by example, the importance of taking a stance that is rooted in rigorous engagement with the full range of ideas about a topic.”
—bell hooks (b. 1955)