Three are migratory subspecies, breeding in the northern United States and Canada and wintering in the southern United States and Mexico. The Mississippi sandhill crane was described as a distinct subspecies in 1972 and there are physiological, morphological, behavioral and other differences between them and other sandhill cranes. The Mississippi sandhill crane is a noticeably different darker shade of gray resulting in a more distinct cheek patch. Despite the limited number of breeding pairs in the wild population, electrophoretic studies indicate a reasonable level of genetic diversity. These studies also show that the Mississippi sandhill cranes posess one gene that is unique to sandhills and another that is different from even the Florida sandhill cranes.
Cranes look superficially like herons and their relatives.
Both are tall, thin, and have long necks and beaks. Despite their appearance, though, cranes are not closely related to herons, and their way of living is quite different. The cranes have a varied diet, depending on the time of the year. They feed year-round on many kinds of plant material like edible tubers and roots, as well as some berries, nuts and fruits. In the spring and summer, they also eat animals found in their native habitats including insects, worms, crustaceans, and other invertebrates.