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More than 100 years ago Robert Ridgway wrote of the rapid loss of Illinois' native prairie and its associated bird species, correctly predicting that undisturbed prairie would soon be very rare in Illinois. In fact, the loss of grassland habitat in Illinois has been even greater than the loss of forest habitat, with much less than 1% of the state's original 21 million acres (Figure 3) of prairie habitat remaining.40 As Ridgway described, populations of many characteristic prairie bird species (Table 3) declined considerably with the initial destruction of Illinois' prairies. Populations of these species have continued to decline in modern times because of recent shifts from mixed agriculture, including hay fields and livestock operations, to today's intensive row crop farming.^41,42

Several species of grassland birds, that were considered abundant in Illinois at the turn of the century, have succumbed to the dramatic changes that have occurred in Illinois' landscape. For example the greater prairie-chicken, once considered "excessively abundant" in Illinois⁴³, is estimated to have reached a peak population in Illinois of 10 million birds.⁴⁴ Today, fewer than 80 birds are believed to occur in Illinois.⁴⁵ Other grassland bird species such as northern harrier, short-eared owl, upland sandpiper, loggerhead shrike, and Henslow's sparrow have also been driven to precariously low population levels in Illinois and are listed as state endangered or threatened species.⁴⁵ Some grassland bird species, that are still considered fairly common in Illinois like the grasshopper sparrow and bobolink are experiencing serious population declines (Table 1). These declines suggest an unsure future for Illinois' grassland birds if proper habitat management measures are not implemented by landowners and managers.

The factors responsible for these grassland bird declines are not entirely understood, but are believed to be due to a combination of loss and degradation of grassland habitat⁴², reproductive failure due to high rates of nest predation and nest parasitism16, and shifts in agricultural practices, such as earlier and more frequent mowing of hay fields that make these species more susceptible to nest failure and other problems.⁴⁶

Current interest and increased efforts to plant and restore prairies and native grass habitats, and government programs to reduce soil erosion through planting, such as the Conservation Reserve Program, offer new hope for grassland nesting birds. However, mid-season cutting of these areas very likely reduces and possibly eliminates successful nesting by birds in these habitats.⁴⁷ Moreover, recent research has shown that grassland plantings and restorations need to be larger than most current efforts if grassland bird populations are to benefit from these efforts.⁴⁸

Management strategies to benefit nongame grassland birds center on protecting or establishing large contiguous grassland blocks, providing structurally diverse habitat, eliminating catastrophic mid-season grassland mowing, reducing edge, and eliminating and controlling woody encroachment. Persons interested in learning more about how to plant prairie habitat should obtain a copy of the publication "Illinois Prairie; Past and Future, A Restoration Guide" from the Illinois Department of Conservation, Division of Natural Heritage.