The Brookville Lake/Whitewater State Park Important Bird Area is located in southeastern Indiana along the convergence of Fayette, Franklin, and Union Counties. In total, this IBA encompasses approximately 20,000 acres of habitat, which includes open reservoir, climax forest, second growth woods, and successional areas, all within the rolling hills, steep ridges, and ravines associated with Indiana?s Bluegrass Natural Region.
The most noticeable feature of this IBA is the Brookville Lake property, which is owned by Indiana?s Department of Natural Resources (IDNR) and totals approximately 17,000 acres. The manmade Brookville Lake stretches in a near perfect north-south direction for about 20 miles, but the reservoir is contrastingly narrow ? only about 1.5 miles wide at its greatest distance from eastern to western shore. Consequently, the lake constitutes just 5,200 acres of the property, and the remaining acreage is mostly uplands reverting back to secondary and older growth forest. Some anthropogenic structures and recreational lands are here, too, comprising the Quaker and Mounds State Recreational Areas.
Whitewater Memorial State Park, this IBA?s other namesake, is located on the northeastern border of Brookville Lake and encompasses about 1,700 acres of land and water. Within this property are tracts of hardwood forest, the smaller manmade Whitewater Lake (200 acres), and the Hornbeam Nature Preserve, which is noted for containing an unusual number of hornbeam and hop hornbeam trees.
The Brookville Lake and Whitewater State Park properties support one of the most significant assemblages of migrant and nesting avian species in eastern Indiana. Congregations of migrant waterfowl, a diversity of neotropical passerines, and nesting endangered raptors are the fundamental characteristics of this Important Bird Area.
Few bodies of water in the eastern half of Indiana rival Brookville Lake?s migrant waterfowl populations, particulary in early spring when daily counts of individuals at this locale can exceed over 2,000 birds. Diving ducks ? especially Aythya species such as Lesser Scaup and Redhead ? are the most prominent of these transients, although sizeable concentrations of American Black Duck, which is part of Audubon?s WatchList registry, are found in the waters of Brookville Lake during migration.
Some stands of secondary and near climax forest exist along the reservoir, especially along Adena Trace at the southwestern edge of Brookville Lake, and these habitats provide critical breeding habitats for many WatchList neotropical migrants. Declining forest interior species such as Wood Thrush, Cerulean Warbler, and Kentucky Warbler are found each summer within these locales. Louisiana Waterthrush breed within the small streams of these forest stands, and Prairie Warblers, another WatchList species, nest in the younger growth of the woodland periphery.
The large reservoir and surrounding trees also provide adequate breeding territories for two of Indiana?s endangered raptors species ? Bald Eagle and Osprey. A single eagle?s nest is occupied annually along the lake, and two Osprey nests have been active over the past few years. The status of the latter species at Brookville is quite significant considering the Osprey nesting population in Indiana likely totals less than a dozen pair.