The Southern Unit of the Kettle Moraine State Forest (KMSF) is the largest block of public parkland and wildlife habitat in the 8-county corner of southeastern Wisconsin, where 6% of the state?s land area is home to approximately 40% of its human population. The South Kettle Moraine was, like its northern counterpart, formed at the meeting place of two lobes of the Wisconsin glaciation. The interlobate moraine and its kettles were originally vegetated with a mix of oak forests and bur oak savannas. West of the moraine, lowland prairies and sedge meadows filled the Scuppernong River basin. Currently, the predominant vegetation types are upland deciduous forests, sedge meadows and other wetlands, native prairies, some savanna, shrub-carr, cool-season grasslands, upland shrublands, and conifer plantations.
The South Kettle Moraine is the match of its North Unit counterpart in importance to birds. It has been estimated that the South Kettle Moraine, holds about 100,000 adult birds of 137 species (including 103 landbird species) during the breeding season (Bielefeldt and Rosenfield 2005). This IBA contains core habitat for Cerulean Warbler, with more than 4,000 acres of available habitat, and also holds the largest population of Hooded Warbler in the state. Work by Bielefeldt and Rosenfield (2001) shows that Hooded Warblers nest here in some decidedly ?non-traditional? habitat types, including in conifer plantations. Grassland birds such as Northern Harrier, Sedge Wren, Henslow?s Sparrow, Field Sparrow, Grasshopper Sparrow, Bobolink, and Eastern Meadowlark also find extensive habitat here, with more than 3,000 acres managed currently as low prairie, sedge meadow, and fen. Savanna restorations are expanding, and may allow species such as Red-headed Woodpecker to increase their numbers. Other high conservation priority species found here include American Woodcock, Yellow-billed Cuckoo, Whip-poor-will, Belted Kingfisher, Willow Flycatcher, Yellow-throated Vireo, Eastern Wood-Pewee, and Wood Thrush (Bielefeldt and Rosenfield 2005). This site also attracts over 200 species of migrating landbirds. Sample counts yielded an estimate of 2.35 million birds utilizing this IBA as migratory stopover habitat during the autumn of 2005 (Bielefeldt 2006).
Many conservation challenges in the Kettle Moraine State Forest involve heavy human use. In the ever more urban landscape of southeastern Wisconsin and northeastern Illinois, the KMSF is a frequent recreational destination for hikers, horseback-riders, mountain-bikers, cross-country skiers, dog trainers, snowmobilers, hunters, and campers. The year-round nature of this human use means the potential for bird disturbance is present during all seasons. Also prevalent here is the incursion of invasive plants. Increasing urbanization and habitat degradation are regional issues with the potential to impact the habitats at this site. This site contains eight State Natural Areas, managed to maintain and enhance ecological communities and native species diversity. The Scuppernong River Habitat Area project, conceived and managed by South Unit and other WDNR staff with the cooperative support of other public and private agencies (WDNR 1991, WDNR and KMNHA 2002), seeks to protect and restore grassland habitat on what is envisioned as the largest complex of native lowland prairie east of the Mississippi River.