** FILE ** A piping plover, an endangered shorebird, runs along the sand at Seawall Beach, in Phippsburg, Maine, Tuesday, June 13, 2006. Two decades after the Atlantic piping plover was declared a threatened species, biologists are now crediting beach closures, twine barriers and other buffers between birds and humans for a 141 percent increase in the piping plover population. (AP Photo/Pat Wellenbach)