This project is Task #7 of SANDAG contract number 5004388: Rare Butterfly Management and Conservation Planning. A summary of this task is provided below. Surveys for Harbison’s dun skipper adults were conducted to assess year to year variation in population size. Field visits were used to document use including plants used for nectar sources, as well as obtain non-lethal genetic samples. A rapid habitat assessment was conducted at each site which included general woodland tree species composition, condition of San Diego sedge plants, and recording potential threats to the Harbison’s dun skipper.
Name: Harbison's Dun Skipper Adult Surveys and Habitat Assessment- 2016
Description: Adult Surveys We conducted surveys for Harbison’s dun skipper adults at sites where we had previously detected adults. Surveys consisted of systematic searches around San Diego sedge patches conducted during periods of appropriate weather (sunny or partly sunny, 24 to 35 degrees C, and modest wind speeds). These surveys will provide an index of population size, help evaluate skipper detectability, and describe the adult flight season phenology, behavior, and nectaring sources. Non-lethal genetic samples were collected from adults in preparation for a landscape genetics project planned for the near future. Larvae of Harbison’s dun skipper are relatively easy to find because of their distinctive hibernaculum. Unfortunately, they tend to have a more diffuse distribution and occur in terrain that is difficult to navigate (canyon bottoms with boulders, fallen trees, and abundant poison oak). Adults tend to leave the canyon bottom to search for flowers on the edge of the oak canopy.
Project type: Monitoring-Animals
Target species: Harbison's Dun Skipper
Target vegetation: oak woodland
Investigator: Douglas Deutschman
Main implementing entity: San Diego State University, Department of Biology
Point of contact: Dan Marschalek
Study lead: Dan Marschalek