Argentina, Aruba, Belize, Bolivia, Brazil, Canada (B) (P), Chile, Colombia, Costa Rica, Ecuador, El Salvador, Falkland Islands (Malvinas), French Guiana, Guatemala, Honduras, Mexico, Netherlands Antilles, Nicaragua, Panama, Paraguay, Peru, Puerto Rico, USA (B), Venezuela.
Vagrant to Australia, Belgium, Cuba, Faroe Islands, France, French Polynesia, Gambia, Germany, Guadeloupe, Haiti, Iceland, Ireland, Japan, Kiribati, Marshall Islands, Micronesia [Federated States of], Morocco, Mozambique, Namibia, Netherlands Antilles, Norway, Portugal, Senegal, South Africa, South Georgia and the South Sandwich Islands, Spain, St Helena, St Pierre and Miquelon (P), Sweden, Trinidad and Tobago, United Kingdom, United States Minor Outlying Islands, Zambia.
Breeds in central North America, wintering mainly in South America.
 
Population
Estimated population is 470,000 - 1,500,000 (2010).
The Field Guide to the Birds of Australia Pizzey, G., and Knight, E., 1997, Angus & Robertson, Sydney ISBN 0 207 19691 5
Field Guide to Australian Birds Morecombe, M., 2000, Steve Parish Publishing Pty Ltd. ISBN 1 876282 10 X
Field Guide to the Birds of Australia Simpson, K., and Day, N., 1999, 6th Edition, Viking ISBN 0 670 87918 5
Reader's Digest Complete Book of Australian Birds 1988, 2nd Edition, Reader's Digest ISBN 0 949819 99 9
What Bird is That? 1984, Revised Edition, Angus & Robertson, Sydney ISBN 0 207 14846 5
Handbook of Australian, New Zealand & Antarctic Birds 1990 - , Oxford University Press, Melbourne ISBN 0 19 553244 9