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) [XC154430]
by Ross Gallardy from Saladillo, Buenos Aires Province, Argentina (alarm call, call)
Snowy-crowned Tern (Sterna trudeaui) [XC22563]
by Fernando Medrano from Reserva Biol\u00f3gica do Mato Grande - Arroio Grande, Rio Grande do Sul, Brazil (call)