Fort Fisher provides a glimpse of the dynamic ecosystem known as a barrier spit where the only constant is change. Sixteen threatened and endangered species can be found at Fort Fisher depending on the time of year. Loggerhead sea turtles nest on ocean beaches in the warmer months and terns, plovers, and oystercatchers use bare sandy areas from the beach to the salt marsh for nesting and foraging. Vast Spartina salt marshes, one of the most productive ecosytems on earth, provide food and shelter for fish and shellfish and shorebirds. Fall brings migrations of warblers, hawks, and peregrine falcons. Winter brings many species of ducks to the marshes. Storms constantly rearrange the landscape, overwashing dunes, opening and closing inlets and channels, and changing the shape of the beach. Native wildlife at Fort Fisher depends on this constant environmental change to maintain the habitat that it requires.