I had the privilege seeing a small cluster of these rare beauties and so I decided to hide a cache in their honor after reading up on them, and learning about their conservation status. Typically, adult butterflies emerge in early spring. The adults, which live an average of 10 days emerge during a six-week period from late February to early May, so if you visit during those months you may be lucky enough to see one for yourself!
The San Bruno Mountain 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 in northern San Mateo County and identifies seven animal species and 44 plant species to be conserved. Among them are the federally endangered Mission Blue butterfly, San Bruno Elfin Butterfly, Callippe Silverspot Butterfly, and the Bay Checkerspot butterfly, but the Bay Checkerspot was not federally listed when the plan was adopted. Thus, this HCP's primary focus is on two of those species of butterfly that were federally listed when it was adopted in 1983, the Mission blue and San Bruno elfin butterflies. Much of the Bay Checkerspot population has declined suddenly since 1986. The causes included fires, non native plant species and natural fluctuations. The reintroduction of the Bay Checkerspot is one of the goals the San Bruno HCP hopes to achieve.
Congratulations to bthomas on FTF!