For many species, American coasts are key places for these birds to rest and refuel before or after an exhausting non-stop flight. Migratory birds need quality habitat in wintering areas, breeding grounds, and at critical stop-over locations along their migration routes. Coastal woodlands and barrier islands on the Gulf coast are critical places for these birds to rest and refuel. High Island, Texas, and Horn Island, Mississippi, are two important rest stops for many spring migrants. Huge numbers of birds are funneled down the Cape May and Delmarva peninsulas, making these key stops on the fall migration route for many spring migrants.
Shorebirds are particularly dependent on just a few critical stop-over locations.
Other critical shorebird stop-over sites include the Copper River Delta in Alaska, Gray's Harbor in Washington, and the Bay of Fundy in Canada. In recent decades, concern has grown as annual bird counts reveal sharp declines in the numbers of once common birds. Fragmentation, degradation and loss of habitat in both Latin and North America is thought to be the single most important factor contributing to the decline. Other problems confronting neotropical migrants include pollution, competition with exotic species, collisions with buildings and automobiles, hunting and control as agricultural pests, and increased rates of predation and parasitism caused by feral animals, exotic species, and degraded habitat. Annual surveys show that the populations of some migratory species began to decline around 1980 at alarming rates, an average of 1 to 2 percent per year.