There are so few Bay checkerspot butterflies left in the Bay area that the U.S Fish and Wildlife Service recommended in October the species should be changed from threatened to endangered under the Endangered Species Act, the San Francisco Chronicle reports.
Once common in the Bay area, the checkerspot now is restricted mostly to a small population along Highway 101 near San Jose. The once-thriving colony at Jasper Ridge Biological Preserve in Palo Alto, the subject of decades of study in island biogeography and gene flow by ecologist Paul Ehrlich, was declared extirpated in 1988. The Bay checkerspot is restricted to serpentine grasslands, where its native larval host plants (Plantago erecta, Castilleja spp.) and adult nectar plants (Lasthenia californica, Linanthus parviflorus, Layia platyglossa) persist. In many areas, these natives are being out-competed by invasive Eurasian grasses.
Read the full story at 2009 Oct 21 SF Chronicle_Bay Checkerspot recommended for endangered status