Butterfly (Lepidoptera: Lycaenidae, Nymphalidae, and Satyridae) Faunas of Three Peatland Habitat Types in the Lake Superior Drainage Basin of Wisconsin

The butterflies which complete their entire life cycle within peatland habitats were documented in the Lake Superior drainage basin of northwestern Wisconsin. Seventy peatlands were inventoried over the course of the 1996 growing season, and were classified as either muskeg, kettlehole, or coastal sites. Muskeg peatlands were of similar elevation to the surrounding uplands, possessed drier and more nutrient-poor substrates, and were typically larger than other peatland types. Kettlehole peatlands were wetter and had floating Sphagnum mats which fringed lake margins or were in depressions much lower than the surrounding uplands. Coastal peatlands were located in estuaries along the Lake Superior coast, and possessed relatively eutrophic, wet soils. Muskeg sites harbored the most diverse total fauna, and possessed the highest average number of taxa per site. A highly significant correlation between habitat size and butterfly richness was observed in both muskeg and kettlehole peatlands. The muskeg fauna included five taxa not found in other peatland habitats. These species have arctic-boreal affinities and reach their southern range limit in eastern North America on these sites