Population structure of the rare, narrow endemic Hermes copper butterfly (Lycaena hermes)

Hermes copper butterfly (Lycaena hermes) has an extremely restricted range, inhabiting coastal sage scrub adjacent to San Diego, CA USA. Habitat loss due to urbanization and the increasing frequency of wildfires have increased the risk of extinction prompting a federal review for potential protection under the Endangered Species Act. Recolonization of post-wildfire habitats by migrants from extant populations -prior to extirpation themselves by wildfires- is critical for the long-term persistence of the species. Past research has shown that adults typically move shorter distances but further movements are possible across undisturbed habitat. Traditional marking techniques are insufficient to detect long distance dispersal (ca. greater than 2 km) events, a phenomenon of considerable importance needed to understand the impact future fragmentation and wildfires will have on the distribution of Hermes copper. Using a molecular technique, amplified fragment length polymorphism (AFLP), we are able to indirectly assess the dispersal ability and patterns of the species. We found patterns of genetic differentiation among populations inconsistent with general isolation-by-distance models. Moreover, we are evaluating the temporal variation of allele frequencies as genetic drift and/or dispersal may be variable from year-to-year.