[order] Charadriiformes | [family] Sternidae | [latin] Sterna albifrons | [UK] Little Tern | [FR] Sterne naine | [DE] Zwergseeschwalbe | [ES] Gaviotín Chico | [IT] Fraticello | [NL] Dwergstern

Dwergstern determination

copyright: Don DesJardin

Archetypical small tern. Small, with white forehead. 21-27 cm, 45-60 g, wingspan 45-55 cm. Black cap and lores, grey back and wings, white rump, and white underparts. Bill bright yellow with small dark tip. Legs and feet orange-yellow to yllow. Deffers from S.saundersi in white of forehead reaching behind eye, less black on primaries, and usually brighter yellow legs. Races differ little. Shafts of outer 3 primaries dark brown to brownish white in nominate, but white in pusilla and sinensis.

Subtropical to temperate regions. Continental populations mainly coastal, but also inland along rivers and on oceanic islands. Breeds on barren or sparsely vegetated sandy, shell, rocky and coral islands, shingle beaches, spits in estuaries and lakes, salt-marshes and rivers. Outside breeding season, frequents tidal creeks, coastal lagoons and salt-pans.

Sterna albifrons is a widespread but patchily distributed summer visitor to much of Europe, which accounts for less than half of its global breeding range. Its European breeding population is relatively small (<55,000 pairs), and underwent a moderate decline between 1970-1990. Although the species was stable or increased across much of Europe during 1990-2000, sizeable populations in Russia, Turkey and Italy declined, and the species underwent a moderate decline (>10%) overall. Consequently, it is evaluated as Declining.
This small tern has a wide but very fragmented distribution in Europe and southern Asia. It inhabits marine coasts and sand or gravel banks of large inland rivers. European birds winter along the coasts of West Africa. The population of the European Union is estimated at 13000 breeding pairs, which represents about half the total European population. After it declines during several decades, this species is increasing again since the 1970's. However, its breeding sites are often very temporary, and this species is undergoing important fluctuations affecting its numbers and distribution as well. Its main threats are canalisation of rivers, pollution and tourism development

Diet based on small fish and crustaceans, also molluscs, annelids and insects. Main fish perch, rudd, roach and sandeels. Forages by quartering back and forth over water, specializes in prolonged hovering and plunge-diving into shallow water, often at edge of advancing tide. Takes insects from vegetation and waer surface by aerial-dipping.

This species has a large range, with an estimated global Extent of Occurrence of 1,000,000-10,000,000 km˛. It has a large global population estimated to be 140,000-410,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

Breeds May-June in Europe and India, April in West Africa, in small to medium sized colonies. Forms synchronous subcolonies, usually monospecific. Nest usually bare, but in marshes builds on platorms of shell or vegetation. 2-3 eggs are laid, incubation 21-24 days. Chicks are creamy-grey or white with sparse or dense black spots. First breeding 3 years.

Migratory. West European populations winter in West Africa, probably also South Africa. East European and west FSU populations winter in Red Sea and southern Arabia (and may occur in East Africa). Autumn passage mainly August to early October, most following coasts but some crossing central Europe via river valleys. Spring passage mainly April-May; more rapid and more strictly coastal than in autumn.