You may be surprised at an unusual connection between our Donald Von Raesfeld power plant and the endangered bay checkerspot butterfly. The butterfly once lived in many areas around the San Francisco Bay from Contra Costa County to Hollister, but is now primarily found only in the foothills of southern Santa Clara County. How this colorful butterfly became threatened is a tale of air pollution and invasive plant species. How it is being saved is a story that intertwines native grassland preservation with cattle grazing.
Here’s how it works.
The bay checkerspot requires certain native grasslands that grow only in nutrient-poor serpentine soil in the area. Unfortunately, the nitrogen oxide from vehicle emissions on nearby highways enriches the soil, allowing invasive plants to grow and choke out the native plants needed by the butterfly for food and shelter.
Stanford University researchers identified the resulting drastic decline of the butterfly in the 1960s, leading to the bay checkerspot being federally designated as threatened in 1987. Researchers also found that cattle grazing improved the butterfly habitat, as cattle preferred to eat the non-native invasive plants and did not like the native plants that are home to the checkerspot.
Here’s where our DVR power plant enters the narrative.
While the modern power plant does not emit anywhere near the volume of nitrogen generated by traffic, the federal government still required us to offset DVR’s emissions with a Habitat Conservation Plan. Our staff saw this as an opportunity and we purchased 40 acres of butterfly habitat east of Highway 101 and donated it to the Silicon Valley Land Conservancy for permanent protection. Of course, cattle are welcomed on the land to dine to their hearts’ content on the invasive plants.
The U.S. Environmental Protection Agency has a wealth of information on their website about the checkerspot butterfly and its prospects for survival. We’re happy to be a part of the efforts to protect this South Bay Area butterfly.
By the way, we recently published a blog post about the many community benefits associated with DVR. We can now add the bay checkerspot butterfly as one of the benefactors of our locally owned and operated electricity generating facility.