ternes

Terns are a widespread group of seabirds belonging to the family Laridae, closely related to gulls and skimmers. They are characterised by slender bodies, long pointed wings, forked or deeply notched tails, and sharp, pointed bills adapted for catching fish. Most species exhibit a streamlined profile and a graceful, agile flight, often hovering briefly before plunging into water to capture prey.

The family comprises approximately 45 species distributed across all major oceans, as well as inland lakes and rivers. Terns occupy a variety of habitats, ranging from coastal cliffs and sandy beaches to river estuaries and inland wetlands. Many species are migratory, travelling thousands of kilometres between breeding and wintering grounds; the Arctic tern (Sterna paradisaea) holds the record for the longest annual migration, moving between the Arctic and Antarctic.

Breeding behaviour is typically colonial, with nests built on the ground, in vegetation, on cliffs, or on floating platforms. Both parents share incubation duties, and fledging is rapid, allowing chicks to become independent within weeks. Colouration varies among species: many display a contrasting black cap, white underparts, and muted grey or brown upperparts, while others possess more extensive plumage patterns and seasonal changes.

Terns play a significant ecological role as predators of small fish, crustaceans, and insects, influencing aquatic food webs. They are also bioindicators of marine health, as their populations respond to changes in fish availability and habitat quality. Conservation concerns include habitat loss, disturbance from human activity, predation by invasive species, and pollution. International agreements such as the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) and various national protections aim to safeguard vulnerable tern species and their breeding sites.