Date of this Version
The interior least tern (Sterna antillarum) and the piping plover (Charadrius melodus) are federally endangered and threatened species, respectively, which nest on sandbars in the Missouri River. This nesting habitat has been decreasing in past years, at least in part due to vegetative encroachment. Vegetation is no longer regularly scoured from sandbars by heavy spring flows and/or ice, primarily because flows are regulated by the main stem dams. New sandbar creation is uncommon because the river carries less sediment and is no longer meandering along much of its course. Bank erosion still continues to supply sediment along "natural" segments of the Missouri River; however, the reservoirs collect much of the incoming sediment, so little passes on to the river downstream from the dams. The combination of vegetation encroachment and reduced island formation result in less suitable nesting habitat for these two bird species.