Common Tern

How to find it

Start at Puntarenas, where birders scope the water from the overlooks near the lighthouse at the end of town. Morning and late afternoon are best, when birds come closer to shore. Some birds sit in distant flocks, so a telescope helps. The Puntarenas to Paquera ferry is also a good way to see seabirds. Check boats, buoys and piers for perched terns, and try the river mouth by the Caldera beach, where close comparison with other terns has been possible.

How to recognise it

A breeding adult is pale gray above and paler below. It has a black cap, orange-red legs and an orange-red bill with a black tip.

In non-breeding plumage the forehead and underparts turn white. The bill is black, sometimes with a dark red base, and a dark bar shows on the front edge of the wing.

In flight, look for a dark wedge on the outer primaries and a white rump against a gray back. The tail streamers are fairly short. When the bird is perched they do not reach past the wingtips, a handy check when you are sorting terns on a pier or beach.

What it sounds like

Recording: Alexandr Stanislavschi, CC BY 4.0, source, read 4 Nov 2026.

Behaviour and diet

The Common Tern feeds mainly on small fish. It hovers over the water and then plunges in from above to take them.

Outside the breeding season it needs only places to fish and somewhere to land. It often perches on boats, buoys and piers, as well as on beaches and rocks.

Young Common and Arctic Terns often spend their first summer on the wintering grounds, which may explain immature terns seen off Puntarenas in June.

Where it lives

In Costa Rica this is a bird of the Pacific coast. Terns and gulls feed on the tidal flats there, especially in the Gulf of Nicoya and Golfo Dulce, though that general guidance does not name this species.

Common Terns have been seen from the Puntarenas lighthouse and at the river mouth by the Caldera beach. Cabo Blanco, at the southern tip of the Nicoya Peninsula, is named among the places where seabirds, this tern included, are easy to see.

Across its wider range it breeds in Europe, Asia and North America and winters on tropical and subtropical coasts.

When to see it

An older review calls it a locally common, widespread migrant in spring (March to May) and fall (August to November). Another summary places migration from late September to mid-November and again in April and May, and birders have logged it at Puntarenas in early and late September.

Similar birds

Forster's Tern is also a Costa Rican migrant. It has a thicker bill and paler primaries, and its tail extends past the wingtips when perched, while the Common Tern's tail barely reaches them. In non-breeding plumage Forster's shows a black eye patch on a white head and has a harsh, rasping voice. Arctic Tern has much shorter legs, a lighter flight, a thin black line on the trailing edge of the wing and higher, squeakier calls. The Costa Rica list marks Arctic Tern as uncertain, so the Common Tern is the likelier of the two.

Names and lore in Costa Rica

Besides charrán común, Spanish speakers call it golondrina marina (sea swallow) because of its light, agile flight. This is a general Spanish name, not one tied to Costa Rica.

Status and conservation

The official Costa Rican bird list gives it the status M, migratory, and worldwide its conservation status is Least Concern.

Photography tips

Morning and late afternoon bring birds closer to shore, so those are the hours for pictures. Perched terns on boats, buoys and piers give a steady subject, and the river mouth by the Caldera beach has allowed close looks.