Located in Porter County along the southern shore of Lake Michigan, Indiana Dunes State Park encompasses 2,182 acres of unique landscape and habitat. The park boundary begins at the northern terminus of State Road 49 and is bordered to the north by approximately three miles of beach frontage. The best ecological feature of the park, though, is the Dunes Nature Preserve which encompasses 1,530 acres and is located entirely within the park's boundaries. A mosaic of habitats, including a high-quality dunes ecosystem, herbaceous marsh, swamp, and upland forest, combine with the significant geographical features of the site to create a unique area for migratory and nesting birds.
Perhaps due to its varied habitats and location at the northern part of the state, the most distinctive ornithological feature of Indiana Dunes State Park rests in the fact that many southern bird species, including such WatchList species as Prairie Warbler and Louisiana Waterthrush, inhabit the area during the breeding season along with species considered more northern in their distribution - such as Blackburnian Warbler and Canada Warbler (also a WatchList species). In fact, Indiana Dunes State Park is probably only one of two spots in the state which holds this distinction; the other area is the Sugar Creek valley, which is also being evaluated as an IBA.
This facet of Indiana Dunes State Park makes for a diverse mosaic of breeding birds, and the list of species contains many of conservation concern. Species not previously mentioned which inhabit IDSP during the nesting season include Red-shouldered Hawk, Willow Flycatcher, Wood Thrush, Cerulean Warbler, Black-and-White Warbler, and Prothonotary Warbler; each is either listed as state endangered or continentally threatened.
The property also supports many species of migratory birds during both spring and fall seasons. Golden-winged Warbler and Bay-breasted Warbler are two examples of WatchList species which can regularly be found during these times. The most critical migratory species discovered, though, was a Kirtland's Warbler during May of 2003.
In addition to transient birds staging at the Dunes, the migratory funnel created by the Lake Michigan shoreline brings impressive numbers of migrant hawks over the property during the spring. Sharp-shinned, Broad-winged, and Red-tailed Hawks are typically the most prevalent with single day high counts approaching, or on some occasions exceeding, 100 individuals for each species.
The migratory funneling created by the deep and elongated waters of Lake Michigan also affects waterbird and passerine migrants. On most spring days when the prevailing winds are from the south or west, diurnal migrants can be seen following the shoreline along the northern edge of the park; in addition, nocturnal neotropical migrants can also be seen searching for daytime feeding and roosting sites. Indiana Dunes State Park has become a leading place for birders and ornithologist to survey these "long-shore" flights. When conditions are appropriate, hundreds or even thousands of individuals for common species, such as Blue Jays and Cedar Waxwings, can be observed navigating the shore, while rarities like Marbled Godwit and Loggerhead Shrike are sometimes discovered.
Largely due to its location along the Lake Michigan shoreline and the consequential proximity of heavy industry, the major threats which the birds and respective habitats of Indiana Dunes State Park face are related to industrial pollution. Several large steel mills are located along the lake to the west of the park, and an active coal-powered electrical generating station can be found just a few miles to the east in Michigan City, Indiana. Such industrial plants likely have impacts on the quality of air and water which support the delicate vegetation of the duneland and wetland ecosystems.
However, the miles of golden sand beach and unique mixture of plants and animals along the southern coast of Lake Michigan draws many visitors to the park and hopeful resedential developers to the surrounding environs. Expansion of housing in nearby duneland communities could cause future problems for the quality of the habitat at the park by further isolating it from nearby natural ecosystems.