Species Spotlight: Poweshiek Skipperling

By Allison Raeck, MNA Intern

To me, one of the most interesting things about the outdoors is its variety. Each species provides a vital link in its habitat, regardless of how small it may be. One of Michigan’s tiny yet fascinating creatures is the Poweshiek skipperling.

Though moth-like in appearance, the Poweshiek skipperling is a small butterfly that resides in tallgrass prairie. Its upper wings are a dark grayish-brown tone, with orange markings on the forewing. A distinctive pale area on the butterfly’s hindwing sets it apart from moth counterparts, as does a dark green stripe on Poweshiek skipperling caterpillars. Males and females are very similar in appearance, as they both have a wingspan of roughly one inch. However, females can be identified by a subtle brand on the forewing.

A Poweshiek skipperling on a black-eyed Susan. Photo: Dwayne Bagdero.

A Poweshiek skipperling on a black-eyed Susan.
Photo: Dwayne Bagdero.

The main flight period for the Poweshiek skipperling is mid June to mid July. During this time, the butterfly can be spotted fluttering low in the grass near nectar sources, especially tending to prefer black-eyed Susan flowers in Michigan. Its flight involves excessive wing movement that exerts little forward velocity, distinguishing the species from other butterflies and moths. This slow, bouncy pattern resembles skipping, which gives the Poweshiek skipperling its name.

The butterfly has been sporadically reported in various areas throughout the Midwest, as far east as Ohio and as far west as Minnesota. In Michigan, the Poweshiek skipperling resides in select prairie fens in the southeast region. These fens are wetland communities mainly composed of sedges and grasses, and are one of the most biologically diverse ecosystems in Michigan. Prairie fens house over two dozen of the state’s rarest plants and animals, including the Poweshiek skipperling.

However, because Michigan Poweshiek skipperlings are limited to this specific prairie fen habitat, they are experiencing a severe population decline and are currently state threatened. Prairie fens are extremely delicate areas, limited by invasive species, gravel mining, and woodland invasion. Without scheduled burn or mow periods, fen plants grow too tall to house this sensitive insect, limiting their survival.

Addressing this concern, MNA protects prairie fens in 14 of its sanctuaries in southern Michigan. In order to prevent the fens from succeeding into forest or shrubland, MNA holds prescribed burns of these areas. Though some of MNA’s especially sensitive fens have restricted access, Lefglen Nature Sanctuary, Lakeville Swamp, and Goose Creek Grasslands are all open to the public. MNA also holds scheduled field trips and work days in many of these areas, including upcoming volunteer days at Goose Creek Grasslands, located in Lenawee County, on June 10th and June 14th.  These visits allow guests to help protect these delicate habitats.

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MNA Staff Begins Burn Season at Big Valley

By Mitch Lex

Photo courtesy of Eugene Lidster

On Thursday March 22, Stewardship Coordinator Andrew Bacon set out with fellow MNA Regional Stewardship Organizers Katherine Hollins and Matt Schultz to conduct the first set of controlled burns of the season. One of them was at Big Valley Nature Sanctuary. With the assistance of five volunteers, the stewardship staff was able to successfully burn 10 acres of the Big Valley sanctuary—a process that is vital to the ecological health of the prairie fen and oak upland communities found there.

The essential burn invigorates the native flora and fauna at the sanctuary by damaging the encroaching woody overgrowth, and creates additional opportunity for sun to infiltrate the understory and create future habitat. Without prescribed burns, hardwood canopies can become too dense and crowd out the essential undergrowth altering the composition of the prairie and forest floors. Invasive species such as the autumn olive and dogwood are kept in check by prescribed burns.

Photo courtesy of Eugene Lidster

Several rare insect species found at Big Valley Nature Sanctuary as well as numerous species of snake also depend on burning for the long term survival of the population. The endangered tamarack tree cricket and poweshiek skipperling both rely on the open canopy characteristics found in prairie fens at Big Valley. To protect reptiles, insects and other species that have difficulties escaping burns, MNA patrols the burn unit prior to the burn and moves individuals out of the area. Smaller units are burned in sanctuaries with fire-sensitive species to protect the overall population. Backing fire is used as much as possible in sites with more reptiles, giving them more time to take cover.

Photo courtesy of Eugene Lidster

Although prescribed burning is essential to the protection of many of MNA’s sanctuaries, it does not come without risk. The MNA staff plans out burn units several months in advance and must track the burn history of each sanctuary to ensure the areas of most concern are being treated. Following a burn, MNA monitors the results.