The Great Lakes piping plover population (Charadrius melodus) was listed as federally endangered in January 1986. At the same time, the Great Plains and East Coast piping plover populations were granted threatened status. By the time listing occurred, plovers in the Great Lakes region were nesting only at sites within the state of Michigan. Piping plovers previously nested at locations in Michigan, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, New York, and Ontario, Canada. The Duluth Harbor, Minnesota nesting site along Lake Superior supported nesting piping plovers as recently as 1985, but no plovers have bred there in the past six years. Piping plovers historically nested along the shorelines of all the Great Lakes, but estimates of pre-development population sizes are limited. However, it is speculated that piping plovers were once locally common throughout the region. The Great Lakes piping plover population had decreased to 38 pairs in Michigan by 1979, and to 17 pairs by 1986. The population has remained relatively stable since its listing in 1986. In 1990 the population decreased to 12 pairs of adults and one of these pairs was lost to great-horned owl predation. The population is now extremely vulnerable to stochastic events that may occur throughout stages of the life cycle and may have reached a size where natural recovery is unlikely.