An endangered species is any species that is at risk of extinction because of a sudden rapid decrease in its population or a loss of its critical habitat. Loss of habitat and loss of genetic variation leave these species vulnerable. A threatened species is any species generally believed to become endangered within all or much of its range in the near future.
In Illinois, the Illinois Endangered Species Protection Act (520 ILSC 10/) was enacted to help protect those species of plants and animals native to Illinois which are in danger of being lost from the wild in the state.
These documents provide more information about endangered and threatened species in Illinois.
Illinois Department of Natural Resources Endangered and Threatened Species
Illinois Department of Natural Resources Species Recovery Program
Illinois Endangered Species Protection Board
U.S. Fish & Wildlife Service Midwest Region Endangered Species
U.S. Fish & Wildlife Service Midwest Region Endangered Species: Fact Sheet: Rusty Patched Bumble Bee
Guidelines for Enhancing and Creating Nesting Habitat for Blanding’s Turtles in the Northeastern United States in the Context of Regional Conservation
Illinois County Distribution: Federally Endangered, Threatened, and Candidate Species