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Joan St. Hilaire – USFS Jeff Bernatowicz – WDFW William Moore – WDFW - page 4 / 35





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o In 2008, adult Mardon Skippers were first observed June 16th at 2970’ to 3275’ elevation (Appendix A, Tables A & B). Adult Mardons were not seen at 3500’ elevation (Minnie Meadows) on June 17th, but were fairly numerous at this site on June 24th. Although adult Mardon skippers could be observed at Bear Creek 1 (3275’), Minnie Meadows (3500’), Pinegrass 1 (4050’) and Conrad finger 2 (4060’) during the same time period (late June, early July); the emergent date and peak flight period varied by elevation (Table 5). While Mardon numbers didn’t dramatically change between the first and second visits at Bear Creek 1 and Pinegrass 1, their wing wear did. The later visit had butterflies with more wing wear than the first visit at these two sites. The upper elevations of Pinegrass (~5000’) were somewhat different. The first visit to the 767 Road site (Dr James’ first site) on July 11, 2008 found few Mardon skippers all with heavy wing wear. The second survey to this site on July 17th found Mardons fairly numerous with mixed days of emergence based on wing wear. Surveys of other high elevation, Pinegrass Ridge sites on July 17th, also found individuals, with a variety of wing wear and both sexes present. During 2008, adult Mardon skipper numbers probably peaked around June 16 at 2973’, June 24th at 3350’, June 30th at 3500’, July 9-11th at 4060’. It is likely that the flight period on upper Pinegrass Ridge (above 5000’) extended until at least July 24th, if not early August (Table 5).

Potter et al. (1999) reported very similar results for historic sites in Yakima County. Mardon skippers were flying between June 25 and July 5 at 3600’. Data in Potter et al. (1999) is limited, but numbers appeared to peak about June 30th at 3600 feet. At higher elevation sites (4700’-5000’), Potter et al. (1999) reported Mardons found June 24th and July 23rd (Appendix, Table B).

o Our finding concerning the life history of Mardon skippers on the NRD concur with the conservation assessment (USDA Forest Service 2007b). We found weather to be a significant factor influencing the timing of Mardon’s emergence. In 2007, temperatures briefly warmed to 800-900f from June1-5, corresponding with a June 2nd observation in Conrad Meadows at 4000 feet (Appendix, Table B). In 2007, temperatures then cooled until hot weather returned June 20th. Temperatures remained warm for the majority of the 2007 season. Spring-summer 2007 was also the driest on record. The dry conditions combined with hot weather in early June and early July probably shortened the vegetation growing season and Mardon flight period.

Spring 2008 was the inverse of 2007 (Table 1). Spring 2008 was very cold through early J u n e . O n J u n e 1 1 t h a n d 1 2 t h , 2 0 0 8 t h e h i g h t e m p e r a t u r e s a t G r e e n L a k e a n d W h i t e P a s s E a s t w e r e 3 9 0 - 4 2 0 F . T e m p e r a t u r e s f i n a l l y s t a r t e d t o w a r m o n J u n e 1 3 t h . B a s e temperature, it is unlikely that the flight period began much before the first observations on June 16th. Temperatures then stayed warm the remainder of the month, but never got as hot as 2007, even in July. Soils remained moist for much of the year, probably extending the growing/Mardon flight season in 2008. d o n

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