South Dakota Nature Notes
The Dakota skipper is one of the rarest butterflies in North America.
The Dakota skipper is well-named. This small, stout-bodied butterfly is a powerful flyer that seemingly skips rapidly from flower to flower on the Dakota prairies where it can be seen during June and early July.
If you can find one – the Dakota skipper is also one of the rarest butterflies in North America. The Dakota skipper once ranged from northeast Illinois to southern Saskatchewan, but now is found most often only in western Minnesota, northeastern South Dakota and eastern North Dakota.
Mid-June to early July is a good time to look for a Dakota skipper – that is the brief flight period of the adult butterflies that can last up to three weeks (often less). They are tawny-orange to brown butterflies with a one-inch wingspan. Their flight is distinctive: fast wing beats that seem to blur, they move so quickly.
The Dakota skipper actually spends most of its life as a caterpillar. The larvae hatch from eggs in late July and feed at night on grass leaves until late summer or early fall when they become dormant. The caterpillars overwinter near the ground in shelters constructed of silk and debris usually at the bases of native bunch grasses. Come spring, they continue their development until pupating in June.
Then the adults emerge and begin their brief, busy life. This is when they feed and breed; if food resources are sufficient, a female Dakota skipper may lay up to 250 eggs to launch the next generation in July. Good nectar sources are critical. Dakota skippers will visit a wide variety of prairie flowers but are especially attracted to narrow-leafed purple coneflowers. Other good nectar sources include wood lilies, harebells and blanketflowers.
These are plants found in either moist bluestem prairies or dry, upland prairies on ridges and hillsides with needlegrasses. Dakota skippers are dependent upon these habitats; they are a prairie-obligate species. Locations with intact prairie are where to find them, and the Prairie Coteau region in eastern South Dakota is a good place to look: it has been estimated that 50% of the known world population of Dakota skippers lives there. This rocky, hilly region is not good for agriculture, allowing the prairie to persist there that supports these butterflies.
The Nature Conservancy maintains several preserves in and near the Prairie Coteau region. Sioux Prairie is the largest; 200 acres of wetlands and grasslands that support a wide variety of plant and animal life. Aurora Prairie and Altamont Prairie are other good destinations to explore the prairie landscape. Finding rare Dakota skipper butterflies might be difficult, but there are numerous wildflowers, grassland and wetland birds to admire during a visit to these preserves in June.