Piping plovers have been endangered since the 1980s because of increased public use of the beaches these shorebirds nest on, and because of additional predators. Coastal states have worked to conserve the birds — educating beachgoers, installing fencing and closing some parks during breeding season to protect their habitat. In the mid-1980s, there were fewer than 800 pairs along the Atlantic Coast. Today, there are about 2,000 pairs, distributed unevenly.