The Mardon skipper (
) was listed as a state endangered species by the
Washington Fish and Wildlife Commission in 1999 and was designated a Federal candidate for listing under the Endangered Species Act (ESA) by the U.S. Fish and Wildlife Service in that same year. It is also a Region 6 Forest Sensitive species.
Historically, no Mardon skipper colonies were known on the Naches Ranger District (NRD) and only 9 occupied sites were known in Washington (Potter et. al 1999). Surveys by the Washington Department of Fish and Wildlife (WDFW) in 2001 failed to document Mardon skippers on NRD. The closest known colony was in Klickitat Meadows on the Yakama Nation, approximately 5 miles southeast of Conrad Meadows on the NRD. Dr. David James, Associate Professor, Department of Entomology at WSU, identified the first population of Mardon skippers on the NRD, Pinegrass Ridge area, July 19, 2006. The second population was discovered by amateur lepidopterists, Bill and Jeanette Yake June 2, 2007 in Conrad Meadows.
Livestock grazing is one of the potential risk factors identified in the Mardon skipper conservation assessment (USDA Forest Service 2007b). The NRD was in the process of writing a Biological Assessment for the renewal of cattle grazing permits for the Tieton AMP in 2006. The uncertainty of the exact area of Dr James’ site and the possibility of additional sites within the Tieton cattle Allotment prompted the USFS and WDFW to conduct cooperative surveys in 2007. The USFS contracted with the Xerces Society to train observes and conduct surveys in 2007
Concerns over the potential impact of ungulate grazing on Mardon skippers, on the NRD, were elevated in 2007 and spring 2008:
In 2007, the majority of the 38 adult Mardon skippers seen in Minnie Meadows, appeared to favor the area that was excluded by ungulate grazing; majority were seen nectaring on flowers inside a research exclosure. Area outside of the exclosure lacked flowering plants and was heavily grazed.
One of the largest documented concentrations of adult Mardon skippers (457) was found in Conrad Finger 2 on 6/27/07, prior to cattle turn out. On July 10, Xerces Society staff returned to find cattle present, a few flowering plants, and few Mardon skipper butterflies (3 individuals). Biologist from Xerces, USFS and WDFW visited the Conrad Finger 2 and Minnie Meadows Mardon sites September 2007. Several participants of this meeting expressed concern over the level of grazing at these two sites and potential negative impacts it could have on the Mardon skipper.
Another concern surfaced in the spring 2008 when the USFS proposed a turn out date for cattle that was two week earlier then historically in the Pinegrass and South Fork Tieton areas. This change in turn out date was proposed to reduce grazing impacts to the Federally listed bull trout in the South Fork Tieton. Mardon skipper specialists were concerned that this earlier turn out date could have additional negative impacts on the Mardon skippers through trampling and