Aruba, Cape Verde, China (mainland), French Guiana, French Polynesia (B), Indonesia, Japan, Kiribati (B), Malaysia, Marshall Islands (NB), Mauritania, Micronesia [Federated States of] (NB), Morocco, Netherlands Antilles, Northern Mariana Islands (NB), Palau (NB), Portugal (B), Senegal, Spain (B), St Helena, Taiwan (China), Timor-Leste (NB), United States Minor Outlying Islands (B), USA (B).
Vagrant to Australia, Barbados, France, India, Ireland, Italy, Maldives, Netherlands Antilles, South Africa, Sri Lanka, Trinidad and Tobago.
Unknown to Sâo Tomé e Principe (B).
Pantropical: in eastern Atlantic, from Azores south to Cape Verde Is; in Pacific, from eastern China and Bonin Is east to Hawaii, Phoenix and Marquesas Is.
Population
Estimated population is 500,000 - 1,000,000 (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
BirdLife International Species Factsheet