Coast and interior of South America, breeding from south-eastern Brazil and Uruguay to Patagonia, rarely to Santa Cruz, and in Chile (Aconcagua to Llanquihue).
 
Population
Estimated population is 1,000 - 10,000 (2010).
Snowy-crowned Tern (Sterna trudeaui) [XC510848]
by JAYRSON ARAUJO DE OLIVEIRA from Trilha do Talha-Mar, PARNA Lagoa do Peixe, Tavares, Rio Grande do Sul, Brazil (flight call)
Snowy-crowned Tern (Sterna trudeaui) [XC148964]
by Bernabe Lopez-Lanus from Reloca, Cauquenes Province, Maule Region, Chile (flight call)