Species of Concern
Status Assessment Update(2010)
Poweshiek Skipperling (Oarisma poweshiek)
Illinois, Indiana, Iowa, Michigan, Minnesota North Dakota, South Dakota, Wisconsin
by Gerald Selby for the U.S. Fish & Wildlife Service
This report provides an update to the status assessment and conservation guidelines for the Poweshiek skipperling (Oarisma poweshiek) prepared for the U.S. Fish and Wildlife Service (FWS) in 2005 by Gerald Selby (Selby 2005). At the time the original Poweshiek skipperling status assessment was being written, there was evidence for population declines throughout its range. Those declines were especially significant in Iowa and Minnesota, where it appeared that Poweshieks had disappeared from sites known to support healthy populations as recently as 2000 in Iowa and 2001 in Minnesota. Preliminary data from surveys in other states were also showing evidence for declines, suggesting the possibility that negative population trends were widespread throughout the Poweshiek’s range. Recent data (2005-2009) confirm concerns about population trends throughout the range of the Poweshiek skipperling. More recent data were not available for North Dakota, where it was last seen in 2001. At the heart of it range in Iowa, Minnesota, and South Dakota, where it was most abundant and was thought to be most secure, it appears to have disappeared from the majority of sites. Long-term survival of the Poweshiek skipperling may now be dependent on the smaller, more isolated populations at the periphery of its range in Michigan and Wisconsin. Regular surveys have been conducted at many of the sites in those states and most of the populations have remained relatively stable with moderate to low numbers at a time when they have been declining and/or disappearing from the remainder of its range. These data suggest that the Poweshiek skipperling is critically imperiled throughout it range and conservation actions should be a top priority.