Controlled burning and Mardon skipper: Summary of the Mardon skipper Coon Mountain burn site occupancy study 2009-2013

Xerces Society staff monitored the Coon Mountain mardon skipper (Polites mardon, W.H. Edwards, 1881) population in 2009, 2010, 2011 and 2013 to determine the butterfly’s response to a controlled burn conducted by the U.S. Forest Service in 2008.  To study the effects of the burn, the site was divided into four monitoring zones. Each zone was subdivided into burned and unburned areas, and a 150×30 ft. transect was set up in each, resulting in a total of eight transects across the habitat area; four each in burned and unburned areas. Xerces staff counted mardon skippers in each transect and in each zone on two independent monitoring dates in 2009, and on three dates each year in 2010, 2011 and 2013. Although mardon skipper numbers have improved in the burned sites compared to 2009,significantly fewer mardon skippers are still found in burned areas compared to unburned areas in all transects and zones. Xerces recommends that no additional controlled burns within mardon habitat be conducted until populations in the burned area are not significantly different from unburned areas, which may take several more years.