Mitchell's satyr

The Mitchell’s satyr is one of the rarest butterflies in North America. Besides, New Jersey it only occurs in Michigan and Ohio. It has only been documented at two to three locations in northern New Jersey. It has not been observed since 1988.

It occupies limestone (calcareous) wet meadows and fens that feature a dense cover of sedges and scattered shrubs.

Caterpillars feed on sedges of the genus Carex; mostly Tussock Sedge (Carex stricta), which flourish in open wetlands. It is unclear whether adults feed at all, because of their short flight period. If they do feed it would be on fermenting sap or rotting fruit.

The Mitchell’s satyr only flies for a brief period that ranges from late June through mid-July. During that brief period adults mate, lay eggs, and then die. Then the cycle starts again. They generally fly during warm (80º F), overcast days. Males patrol wet meadows while looking for mates. Eggs hatch within 7 to 11 days and the caterpillars feed on sedges through late summer. In fall the larvae go into dormancy (diapause) and resume feeding the following spring. They pupate in June into adults and continue the cycle.

The habitat of the Mitchell’s satyr was historically regulated by natural events to maintain its features. Fire, grazing herbivores, and beavers have all helped keep the satyr’s habitat suitable.

Over time trees and shrubs colonize these open areas and out compete the sedges that the Mitchell’s satyr relies on for survival. Loss of habitat has been the leading cause for the decline of this rare species. In 1991 the Mitchell’s satyr was listed as endangered by both the U.S. Fish and Wildlife Service and New Jersey. Surveys of suitable habitat have not resulted in any new sightings since 1988.