I thought this was a great comparison study photographed and composed by Steve Messick in Colorado. The dark cap of the American contrasts with the supercillium compared with the paler cap of the black-bellied. The Black-bellied also has a grayer overall look and a larger (thicker) bill. The Black-bellied tends to have streaks on a white chest while the American Golden tends to have a mottled gray chest. The Black-bellied has dark armpits in flight. The Black-bellied Plover (Pluvialis squatarola), also known as Grey Plover, is one of a small number of species that are found on every continent except Antarctica.