Behrens and myrtles silverspots are two endangered butterflies on the sonoma-mendocino coast that have suffered substantial range reduction and population decline

This $124,665 three-year Project Grant award from the U.S. Department of the Interior Fish and Wildlife Service under the Endangered Species Recovery Implementation program (CFDA 15.657) aims to restore the endangered Behrens and Myrtles Silverspot butterflies on the Sonoma-Mendocino coast by expanding the coverage of their larval host plant, Viola adunca, in Fort Ross State Historic Park. The project will test the effectiveness of two restoration methods - seed dispersal and planting mature plants - to increase Viola adunca populations and subsequently support the recovery of the two silverspot species. Key activities include establishing recovery sites, applying different treatment plots, monitoring larval presence and butterfly populations, and conducting community outreach to raise awareness about the restoration efforts and butterfly conservation. The results from this study will inform future land management and restoration work in Fort Ross State Historic Park and Salt Point State Park.

Restoration of their larval host viola adunca in fort ross state historic park has the potential to support the population recovery of both butterfly species. The aim of this three-year project is to test the success of two methods (seed dispersal and planting mature V. Adunca) to expand V. Adunca cover and subsequently increase the population numbers of the two silverspots in the state park. Recovery sites (5 X 5 M) will be established where scattered V. Adunca are successfully growing on the coastal prairie grasslands. Within the site, plots of 1 X 1 M will receive either (1) no treatment, (2) seed dispersal (50 seeds M-2), (3) mature plants (grown at fort ross where possible), or (4) a combination of seed dispersal and mature plants with the goal of reaching 20 plants M-2 to support silverspot larvae development. Each year, V. Adunca will be searched for larvae in the spring and butterfly surveys will be conducted near restoration sites in the late summer flight period. Community outreach will be carried out by fort ross conservancy to increase public awareness of these restoration activities and butterfly conservation. By determining the efficacy of restoration techniques as well as looking for any natural recruitment, the results from this study will be used to inform land management and future restoration work in fort ross state historic park and salt point state park.