Large. Long necked, long upcurved bill. Sexes similar.
Adults: Breeding: Head, neck, breast, rusty. Eyering, white. Eye, black. Face at base of bill, white. Underparts, white, with black scapular stripes. Wings, black and white. Bill, black and upturned. Legs, blue-grey, partially webbed. Non-breeding: Like breeding but head and neck, pale grey.
Female: Bill is more upturned than in male.
Juveniles: Like breeding adult but cinnamon parts paler. Terials and coverts have pale fringes.
Anguilla, Antigua and Barbuda, Aruba, Bahamas, Barbados, Belize, Canada (B) (P), Cayman Islands, Costa Rica, Cuba, Dominica, Ecuador, El Salvador, Guadeloupe, Guatemala, Honduras, Martinique, Mexico, Montserrat, Netherlands Antilles, Panama, Puerto Rico, St Kitts and Nevis, St Lucia, St Vincent and The Grenadines, Trinidad and Tobago, Turks and Caicos Islands, USA (B), Venezuela.
Vagrant to Greenland, Jamaica, St Pierre and Miquelon, Virgin Islands (British), Virgin Islands (U.S.).
South-eastern British Columbia east to south-western Ontario, and south to northern Baja California east to central Texas; eastern USA; central Mexico. Winters from California and southern Texas through Mexico to Guatemala and irregularly to northern Honduras; south-eastern USA and Bahamas to Cuba.
 
Population
Estimated population is 100,000 - 1,000,000 (2010).