High Quality Content by WIKIPEDIA articles! The list of threatened fauna of Michigan includes almost 400 endangered, threatened and special concern species that are located in Michigan as a part of the fauna of the United States. Endangered and threatened species in Michigan are protected through the Endangered Species Act of the State of Michigan, part of the 1994 Michigan Natural Resources and Environmental Protection Act. The list was last updated in 2009 to its sixth iteration. At this time, 69 new species were added, including many species of freshwater mussels and snails, and 13 species were removed. The state also recognizes species of special concern, which are not protected under the Act. These species have low or declining numbers in the state or a need for additional information on their populations in Michigan. If the species` numbers decline, they are moved to threatened or endangered status and afforded protection under the Act; if they increase, they are removed from the list without further action.