Common tern fact sheet

Sterna hirundo | Common tern

The common tern is the species of tern most often sighted in the Azores. They are easily identifiable by their red sharp beak with a black tip, red short legs and grey upper body and wings. Their main prey are small fish such as mackerel and boarfish. In smaller quantities they may also feed on sauries, pipefish and seabream. Sometimes they may also ingest mesopelagic fish. Common terns nest around the Azores archipelago between the months of April and August. It is a summer nesting and colonial species. The largest nesting colony is located on the islet of “Praia”, on the island of Graciosa. The common tern is common worldwide, generally nesting throughout the northern hemisphere and migrating the south in the winter. This species is classified as “common breeding” in the Azores.

Length: 32 – 38 cm

Weight: 136 g

Wingspan: 75 – 80 cm

Population:
• Global: c.10,000 reproductive pairs
• Azores: 2,000 – 3,000 reproductive pairs

Longevity:
• Average: 9 – 10 years
• Maximum: 25 years

Diet: Small fish (boar fish, sauries, pipefish), mackerel and seabream

Breeding age: 3 years

Eggs: 2 – 3

Incubation: 3 – 4 years

Fledging: 22 – 30 days