American golden plovers closely resemble Pacific golden plovers (Pulvialis fulva), and the two were originally thought to be the same species. Both have wing undersides that are a grey-brown color and their wings are almost identical in size. American golden plovers have a longer, thinner body with a shorter neck and larger head, a tibia that is shorter than its bill, and a shorter bill relative to head size than Pacific golden plovers.
American golden plovers weigh between 122 and 194 g, averaging 144.6 g. They are 23 to 30 cm in length, and have a wingspan of 45.7 to 66.0 cm with average wingspan being 50.8 cm across.
American golden plovers resemble black-bellied plovers (Pulvialis squatarola) in coloration during the winter breeding season, although they are more golden in color. They are speckled grey and white on their underside (more grey than black-bellied plovers), and are speckled golden, white, and black on the head, back, and tail feathers. In the non-breeding season, American golden plovers appear more golden on their back and head. They lack a wing stripe and males are slightly more colorful than females.
Juvenile stage first non-breeding year plumage is a mix of juvenile and adult-like feathers after a post-juvenile moult. The first pre-breeding feathers look similar to adults after a moult occurs to replace the tail and body feathers of the first non-breeding feathers. American golden plovers have a post-breeding moult, replacing their breeding plumage with an eclipse plumage. This eclipse plumage replaces breeding plumage when they reach their southern wintering grounds. Eclipse plumage is more yellow and brown in color. Females retain more of their winter feathers than males. Males grow new tertials and wing coverts, and females do not. This is why males are brighter in color than females. On their northwards migration in spring, they begin to moult into breeding plumage.
Range mass: 122 to 194 g.
Average mass: 144.6 g.
Range length: 23 to 30 cm.
Average length: 26 cm.
Range wingspan: 45.7 to 66.0 cm.
Average wingspan: 50.8 cm.
Range basal metabolic rate: unknown to unknown cm^3 oxygen/hour.
Average basal metabolic rate: unknown cm^3 oxygen/hour.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male more colorful