Four disjunct populations:
- Galapagos Islands - 50 saline lagoons on Isabela, Santa Cruz, Floreana, Bainbridge, and Rabida Islands. Most breeding occurs on southern Isabela Island.
- Southern Caribbean - Guajira Peninsula of Colombia, N coast of Venezuela, Bonaire, and nearby islands. A small number can be found farther east along the N coast of South America to French Guiana.
- Yucatan Peninsula - N coast, from Campeche to Cabo Catoche, with rare sightings at Sian Ka'an Biosphere Reserve, and on Cozumel Island. Celestun Lagoon and Ria Lagartos Lagoon appear to be the most important localities, containing up to 75% of the population at a given time.
- Northern Caribbean - Bahamas, Hispaniola, Cuba, Turks and Caicos, and southern Florida (probably escaped captives).
Only four main breeding sites:
- Great Inagua, Bahamas
- Archipelago de Camaguey, Cuba
- Rio Lagartos, Yucatan, Mexico
- Bonaire, Netherlands Antilles
Smaller numbers breed in other areas within their overall range.
- Native to Florida (Whitfield et al. 2018)