Common Tern

Overview

The Common Tern is an elegant, medium-sized seabird widely distributed across the temperate Northern Hemisphere. Known for its slender build and deeply forked tail, this migratory species is frequently observed hovering over water before performing steep, agile dives to capture prey.

Distribution & Habitat

This species has a circumpolar breeding range, nesting across North America, Europe, and Asia. It is highly adaptable, nesting on various flat, sparsely vegetated surfaces including sandy or rocky beaches, marsh islands, and inland lakes. They also readily utilize artificial structures like floating rafts and dikes. During the non-breeding season, they migrate to tropical and subtropical coastal regions.

Appearance

Breeding adults are characterized by a black crown, light gray upperparts, and white underparts. They possess a narrow, pointed bill—typically orange-red with a black tip—and vibrant orange-red legs. Juveniles and non-breeding adults generally exhibit a darker bill and a brownish or blackish nape.

Biology & Behavior

Common Terns are gregarious, nesting in colonies that can range from a few pairs to thousands of individuals. They are monogamous and often defend their nesting territories aggressively, diving at intruders. Both parents share incubation duties and continue to feed their young for several weeks after the chicks fledge.

Feeding

Primarily piscivorous, these birds feed on small fish, which they snatch from the water surface after a plunge dive. While fish make up the bulk of their diet, they are opportunistic feeders and may also consume crustaceans, squid, and insects caught in flight.