Karner Blue - Distribution and Habitat

Distribution and Habitat

The Karner blue butterfly occurs in isolated populations in Miller Beach, Indiana, eastern Minnesota, Wisconsin, Indiana, Michigan, and New York. Reintroductions have been initiated in Ohio and New Hampshire. The Karner blue butterfly appears extirpated from Iowa, Illinois, Pennsylvania, Massachusetts, Maine, and Ontario.

Although Karner blue butterflies are characteristic of oak savannas (Quercus spp.) and pine barrens (Pinus spp.) habitats, they also occur in frequently disturbed areas such as rights-of-way, old fields, and road margins. In east-central New York, Karner blue butterflies occurred in 3 rights-of-way habitat types: wild lily-of-the-valley-starflower (Maianthemum canadensis-Trientalis borealis), sweetfern-whorled yellow loosestrife (Comptonia peregrina-Lysimachia quadrifolia), and blackberry-sheep sorrel (Rubus spp.-Rumex acetosella). An index of Karner blue population size was highest in the wild lily-of-the-valley-starflower type. In this habitat, mosses (Bryophyta, 6.9%), wild lily-of-the-valley (4.4%), grasses (Poaceae, 4.4%), and starflower (2.1%) had the highest cover. Coverage in the sweetfern-whorled yellow loosestrife type was dominated by grasses (40.9%), sweetfern (12.1%), mosses (9.4%), and whorled yellow loosestrife (5.2%). In the blackberry-sheep sorrel type, the dominants included grasses (22.7%), northern dewberry (Rubus flagellaris, 5.0%), other blackberries (4.8%), and sheep sorrel (4.3%).