EHL’s sister land trust has brought more land into its “Skyline” project in southeast San Diego County. The threatened Hermes copper butterfly will benefit.

Endangered Habitats Conservancy (EHC) initiated acquisitions for the “Skyline” properties in Jamul in 2014 with a focus on conservation of the rare Hermes copper butterfly. The 3,000-acre Skyline complex represents the last chance to preserve a large, intact landholding in an area now dominated by the sprawling estate lot subdivisions that remain an ongoing threat. As seen on the map below, these properties also help link large cores areas of the San Diego Multiple Species Habitat Conservation Program (MSCP), specifically Sycuan Peak Ecological Reserve, Hollenbeck Canyon Wildlife Area, and Bureau of Land Management lands to the east. 

Five of the seven planned acquisitions have been completed. The remaining two properties could be conserved in 2025. To date, funding of about $13 million has been provided by the state Wildlife Conservation Board, the San Diego Association of Governments, and the County of San Diego.  

Never abundant within its limited range in south-east San Diego, most historical populations of the Hermes copper have been lost. Federally listed as threatened in 2022, surveys in 2023 detected less than 40 individuals range-wide. The butterflies deposit eggs exclusively on their chaparral-community host plant, spiny redberry. The most significant immediate threat to the butterfly is wildfire, which can easily eliminate local populations.  

In 2024, a single Hermes copper was found on one of the new properties EHC intends to acquire and restore. Our plan is to expand spiny redberry and California buckwheat, create Western spadefoot toad habitat, and restore a pond to accommodate translocation of red-legged frogs and western pond turtles. Other species important for the MSCP that are found on Skyline include golden eagle, mountain lion, and Dehesa beargrass.    

These strategic properties stitch together a landscape that gives the stunning Hermes copper a chance to survive.