The snowy-crowned tern, also known as Trudeau's tern, is a species of bird in subfamily Sterninae of the family Laridae, the gulls, terns, and skimmers. It is native to Argentina, Brazil, Chile, Uruguay, and possibly Paraguay, and also vagrant in Peru and the Falkland Islands.
Region
Southern South America
Typical Environment
Primarily found in Argentina, Uruguay, southern Brazil, and Chile, with occasional records farther afield. It uses coastal estuaries, saltmarsh edges, coastal lagoons, large inland lakes, and broad river mouths. The species favors shallow, open waters near sandbars and islands for roosting and nesting. During nonbreeding periods it disperses along coasts and into interior wetlands where prey is abundant.
Altitude Range
Sea level to 1200 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 1/5
Also known as Trudeau's tern, this species stands out among terns for its distinctive snowy-white crown and dark eye-stripe. It frequents brackish lagoons, estuaries, and large inland lakes, often forming loose colonies on sandy or muddy islands. Vagrants occasionally reach Peru and the Falkland Islands.
Temperament
social and active
Flight Pattern
buoyant flier with agile turns and brief hovering before plunge-diving
Social Behavior
Often forms loose colonies or small groups on sandy or muddy islets, sometimes mixed with other terns and gulls. Nests are shallow scrapes on open ground with minimal lining. Pairs display aerial courtship and exchange fish during bonding. Outside breeding, it roosts communally on sandbars and shorelines.
Migratory Pattern
Partial migrant
Song Description
Vocalizations are sharp, clipped kip and kerr calls, especially around colonies. In flight and during displays it gives harsher, rasping notes used for contact and alarm.
Plumage
Pale grey upperparts with white underparts and a clean, snowy-white crown. A contrasting dark eye-stripe runs from the lores through the eye to the ear coverts, with a slightly darker nape. Wings are pale with a subtle darker trailing edge; tail is moderately forked.
Diet
Feeds mainly on small fish captured by shallow plunge-dives and surface-dips. It also takes aquatic insects and small crustaceans when available. Foraging typically occurs over calm, shallow waters where prey schools near the surface.
Preferred Environment
Most often forages in estuaries, lagoons, and broad river mouths with nearby resting sandbars. It also works over large inland lakes and calm coastal shallows, especially where freshwater mixes with brackish conditions.
