Natural History: The Midewin Site
	Although drainage tiles were laid in wet areas of the Midewin site to make them more suited to agriculture, there are still wetland areas at Midewin. (Midewin file)

According to 19th century survey notes, the landscape of Midewin was 86% prairie (including wet prairie and shallow marshes), 14% timber, and less than 1% swamps.

While Midewin's prairie landscape and habitat suitability have become degraded by invasion of alien species, conversion of many areas to agricultural uses, and the break-up of the extended ecosystem due to development of areas surrounding the site, the site still hosts a diversity of landscapes and habitats.

Midewin's prairie complex includes dolomite prairies, one of the rarest natural communities in North America, in addition to grasslands, savanna, wetlands, seeps, upland forests, and three streams. These landscapes today provide habitat for:

• 348 species of native plants
  
  
• 108 species of breeding birds (149 species use the site for breeding, feeding, or wintering)
  
  
• 40 aquatic species, including 9 species of freshwater mussels
  
  
• 23 species of reptiles and amphibians
  
  
• 25 conservative insect species which require native plant communities to survive
  
  
• 27 species of wild mammals

Midewin is home to 16 endangered and threatened species, including the loggerhead shrike. It also harbors Illinois's largest breeding population of endangered upland sandpipers.