Type: report

Article abstract: Surveys for Harbison’s dun skipper adults were conducted to assess year to year variation in population size and to collect non-lethal genetic samples. Field visits were also used to document plants used for nectar sources. The 2017 counts were generally low, and there was not a clear relationship between the 2016 and 2017 counts as some were higher and some lower. We were able to collect 16 genetic samples including the first from Santa Margarita Trail, a second from Fox Springs, and samples three and four from Pamo Valley. Efforts were focused on sites with small populations and few previous samples, likely the reason for the low number of 2017 samples. While past years have been dry, the 2016-2017 winter had several rainstorms, each with several inches of precipitation. Soil and vegetation, including San Diego sedge, were removed in locations, altering the skipper’s habitat within the oak woodlands. It was also commonly observed that the sedge leaves were knocked down by water. Removal of sedge by high water flow is clearly a threat to the skipper, but it is unknown if short-term flooding of the sedge is a threat to the larvae. To provide a complete report, we included all 2017 Harbison’s dun skipper survey data, including our surveys not funded by this project.