Sumru Kuşu (Sterna hirundo)

Common tern is a seabird species belonging to the family Laridae, scientifically known as Sterna hirundo. This species has a wide global distribution and is known for its elegant appearance, long migratory routes, and colonial breeding behavior. In Türkiye, it is recorded as the most common tern species.

Description and Physical Characteristics

The common tern is smaller and more slender than gulls. Its long, narrow wings curve backward during flight, while its body moves up and down in rhythm with wingbeats. While gliding in the air, it lowers its head to spot fish and dives into the water to catch its prey.

• Breeding plumage: The bill is bright red or orange with a black tip. The head is black, the cheeks and throat are white, and the underparts are pale gray. The outer feathers of the wings are dark while the inner ones are lighter; this contrast is clearly visible from both above and below. The tail is long and deeply forked.
• Non-breeding plumage: The bill is black and the forehead is white.
• Juveniles: The base of the bill and legs are orange, and the back feathers are brownish in tone. A broad dark band is present on the leading edge of the wings. The tail is shorter and less forked than in adults.

Adults are known to have long lifespans, with some individuals living up to 25 years in the wild.

Habitat

The common tern is a species capable of adapting to a variety of wetland ecosystems.

• Breeding sites: Nests are built on coastal areas, lakes, lagoons, river mouths, islands, sandy beaches, rocky shores, and areas with sparse vegetation.
• Migration and wintering areas: Primarily observed over open seas, along coastlines, and in wetlands.
• Artificial nesting: Human-made structures such as platforms or protected areas may also be used for nesting.

Distribution

The common tern has a broad distribution across Asia, Europe, and North America. It breeds in northern regions and migrates to Africa, South America, the Arabian Peninsula, the coasts of India, East Asia, and Australia during winter.

In Türkiye, it is observed during summer months and migration periods. Breeding has been recorded in all regions except the eastern Black Sea, western Black Sea, western Mediterranean, and most of Eastern Anatolia. It is particularly abundant around wetland areas.

Diet

The diet consists largely of small fish. It also feeds on insects and crustaceans. During foraging, it hovers above the water surface to spot prey, then dives swiftly to catch it. Occasionally, it has been observed stealing prey from other terns. Large schools of fish can attract hundreds of individuals feeding simultaneously.

Breeding and Behavior

Common terns breed in colonies and, if undisturbed, may use the same nesting sites for many years. They typically lay their eggs on bare ground or in areas with sparse vegetation. Protection of breeding habitats is critical due to human pressure from tourism and coastal development.

This is a migratory species. It arrives at northern breeding grounds between April and June, and returns south after breeding. A small number of individuals are known to remain in the same area year-round.

Conservation Status

Although the common tern has a wide global distribution, populations in some regions are under pressure due to habitat loss and human activities. In certain European countries, the species is considered at risk. Conservation of nesting sites is critical for the continued survival of its populations.