removal of important nectar sources. Regular access of nectar plants is thought to be critical to survival and fecundity of adult Mardons (USDA Forest Service 2007b). To mitigate this concern, cattle exclosures were built around Pinegrass 1 and Pinegrass 2 Mardon skipper sites. An existing, but nonfunctioning, cattle and elk exclosure was repaired in Minnie Meadows during 2008, prior to the cattle turn out dates.
The objectives of the 2008 Mardon skipper surveys were:
Document population numbers over time.
Document the range of Mardon skippers on NRD.
Document new colonies.
Investigate the relationship of grazing and Mardon skippers.
This report provides a summary of each site visited on the Naches Ranger District during the 2008 field season, findings and recommendations for 2009 survey season.
Surveys were conducted according to the Survey Protocol for the Mardon skipper, Version 1.1 (USDA Forest Service 2007a). Sites that were visited by Joan St.Hilaire and/or Jeff (“Bernie”) Bernatowicz are detailed in this report. Visits conducted by Xerces staff are recorded in a separate report (Jepsen et al. 2008), however, results are also discussed in this report. Therefore, there are some overlaps between this report and Xerces report.
o Appendix A, Table A lists all surveys in 2008. Population surveys focused mainly on the Minnie Meadows and Conrad complexes. Other sites were surveyed multiple times opportunistically. There was an obvious start, peak, and decline in adult population counts over 3-4 weeks in the larger populations of Minnie and Conrad Meadows. Minnie Meadows and Conrad peaked about June 30 (187) and July 9 (1840). The Conrad counts were only on the USFS portion of the meadow (Figure 1). Over 50% of the meadow is private and was not surveyed. Both populations declined about 75% 7-9 days later. Given the rapid changes in weekly counts, it is unlikely Minnie meadows/Conrad counts were at exact peaks. Individuals that were present in early surveys were probably gone in later surveys. There is also some difficulty in counting large numbers of Mardons. It should be noted that the later counts in Minnie and Conrad include some Sonora skippers
). The percentage based on sampling was probably <10% Sonora in the
total count. Given all the potential biases, it is difficult to estimate an exact population. A rough estimate would place the actual 2008 population in Conrad at about 4000-5000 individuals.
Smaller populations like Bear Creek 1 and Pinegrass 1 appeared to stay relatively stable over a 2-3 week period. Limited data for upper elevations (767 Road) indicate a possible bi-module population or very extended flight period.