Fly by Nitrogen
Threatened California butterfly hurt by cars and helped by cows
The bay checkerspot butterfly population on Northern California’s Coyote Ridge is threatened with “drive-by extinction,” according to conservation biologist Stuart Weiss. Car commuters to Silicon Valley and other sources of pollution deposit up to 20 pounds of nitrogen per acre on the ridge every year, enriching soil to the benefit of invasive grasses and the detriment of the native plants that sustain the checkerspot. Weiss convinced nearby Calpine Corp. to open a butterfly reserve to mitigate the effects of a planned power plant, and, perhaps surprisingly, he encourages local cattle grazing; cows eat the nutritious invasive plants, leaving the native flora to sustain checkerspot caterpillars. Some of the native habitat of the orange-and-red checkerspot butterfly, which is listed as threatened by the feds, is in the political district of Rep. Richard Pombo (R). We’re just saying.