Common TernSterna hirundoWhere and when to see them

The Common Tern is a slender, long-winged waterbird found along coasts and inland waterways across much of the Northern Hemisphere. European populations are migratory, generally spending the non-breeding season farther south, mainly along African coasts. It occurs in suitable habitats within the Danube, Rhine, Saône and Seine river systems, although its distribution is patchy. Clean water, accessible small fish and safe nesting sites are important to its breeding success. Despite its global Least Concern status, local colonies can be affected by disturbance, flooding, predation and the loss of nesting habitat.

Size

31–35 cm long, with a wingspan of 77–98 cm.

Weight

95–200 g.

Lifespan

Can live for more than 30 years, although many individuals have much shorter lives.

Status

Least Concern (IUCN, global).

Common Terns often breed in colonies, sometimes alongside other terns or gulls. They usually nest in a shallow scrape on the ground, but also use specially managed nesting rafts. During courtship, a male may present a fish to a female. Both parents incubate the eggs and feed the chicks. Adults vigorously defend the nesting area, calling loudly and sometimes swooping at intruders. When feeding, they patrol over water, briefly hover and plunge down to catch prey near the surface. Outside the breeding season, they may gather in flocks at feeding areas and communal resting sites.

• Fish offerings are part of its courtship.
• Both parents incubate eggs and feed chicks.
• Well-managed nesting rafts can support breeding colonies.
• Ringing records document individuals more than 30 years old.

Wildlife opportunities depend on the river reach, water levels and species. River-specific viewing months have not been confirmed; general species seasons are not a local sighting forecast.

This species uses both freshwater and coastal habitats. Along rivers, it favours open water for feeding and sparsely vegetated islands, gravel bars or sandy ground for nesting. Nearby gravel pits, lakes and reservoirs can also provide suitable habitat. Artificial nesting islands and rafts can support colonies where natural sites are scarce. During migration and the non-breeding season, estuaries, lagoons and coastal waters become particularly important.

Small fish form the main part of the Common Tern's diet. It also takes crustaceans, aquatic insects and other small invertebrates when available. Most prey is caught by plunge-diving into the upper layers of the water, although insects may be picked from the surface or caught in flight. Adults carry individual prey items in the bill when feeding a mate or chick.

Common name

Common Tern

Scientific name

Sterna hirundo

Animal group

Birds

Size

31–35 cm long, with a wingspan of 77–98 cm.

Weight

95–200 g.

Lifespan

Can live for more than 30 years, although many individuals have much shorter lives.

Status

Least Concern (IUCN, global).

Identification

A breeding adult has pale grey upperparts, whitish underparts, a black cap and an orange-red bill that usually has a black tip. Its legs are red, and its long, pointed wings and deeply forked tail give it an elegant outline in flight. Non-breeding adults develop a white forehead and a darker bill, while juveniles show brownish or buff-edged upperparts. Compared with the similar Arctic Tern, the Common Tern generally has a longer bill and legs, shorter tail streamers and a darker wedge on the outer upperwing, though identification can require several features.