These diverse wetlands support a breeding avifauna as rich and varied as the wetlands themselves. Other species, such as the northern harrier, marbled godwit, Le Conte's sparrow, and Nelson's sharp-tailed sparrow, are associated with grasslands but extensively use these prairie wetlands.
Dense vegetation reduces the visibility of some species.
Others are colonial, resulting in tremendous spatial variability in their numbers. Thus, no single technique works well for censusing all wetland species. Alkali wetlands were recognized by the occurrence of hypersaline surface water, and fens were identified by a characteristic zone of fen vegetation that develops where groundwater seeps saturate the soil. Although some species were found in all wetland classes, most species showed a preference for one or two classes. 38.6 52.1 673.5 Table 1.