Type: report

Article abstract: The Hermes copper, Lycaena hermes, is a rare butterfly endemic to San Diego County and northern Baja California. This species is threatened by recent urbanization and wildfires throughout its range in the United States (Marschalek et al. 2018). In April of 2011 the United States Fish and Wildlife Service (USFWS) issued a 12-month finding which concluded that listing the Hermes copper butterfly as threatened or endangered was warranted, and is currently on the USFWS list of candidate species (USFWS 2011). Our research has documented several extirpations due to the 2003 and 2007 wildfires, but few recolonizations despite what appears to be suitable habitat. Although a few small populations exist within and north of the city of San Diego, the majority of Hermes copper individuals are found to the east and south east of the city between the fire footprints of 2003 and 2007. Due to the extremely restricted distribution, the species is a high risk of extinction and one more large fire could push the species to the brink of extinction. Recolonization into post-wildfire habitats is essential for the long-term persistence of Hermes copper; however, it appears that habitat fragmentation is limiting dispersal and preventing recolonizations from occurring. For these reasons, we are monitoring four sentinel sites which are well spaced geographically. The spacing provides a range of Hermes copper climatic conditions and reduces the likelihood of being lost in a single wildfire. These data provide information regarding the correlation between annual climate and annual adult population sizes. Also, these data provide important standards to interpret counts from other Hermes copper monitoring and management activities. (TASK 1.3: HERMES COPPER TRANSLOCATION, Contract: F17AC00963 . This project extends the previous SANDAG funded project (Contract #: 5004388 ; Marschalek and Deutschman 2016, 2018), continuing translocation efforts and monitoring sentinel sites. )