Mowing snow … for butterflies
After a flurry of snow covered the Flat River State Game Area, Michigan DNR staff mowed over the snow to benefit the federally endangered Karner blue butterfly.
These pale blue, dime-sized butterflies can only be found in small pockets of savanna habitat where wild lupine grows in the open sunlight. Karner blues depend on lupine for survival, as females lay their eggs on the plant and emerging caterpillars feed on the leaves.
For Karner blue butterfly populations to thrive, the area must be periodically burned with fire or mowed to remove any large woody species that may cast shade on the lupine.
To protect the lupine and over-wintering egg clutches, mowing can only occur when at least 4 inches of snow has accumulated. This winter habitat management activity will produce flourishing native wildflowers and fluttering insects this spring and summer.