Terns (Sternidae)

Common Tern (Sterna hirundo) - HBW 3, p. 652

French: Sterne pierregarin German: Flußseeschwalbe Spanish: Charrán Común

Taxonomy: Sterna Hirundo Linnaeus, 1758, Sweden.
In North America, genetic studies of populations in Minnesota and Wisconsin and ringing studies in NE USA reveal high degree of gene flow, despite colony site tenacity. C Asian minussensis often considered to be no more than a hybrid form between nominate hirundo and longipennis. Four subspecies normally recognized.

Subspecies and Distribution:

hirundo Linnaeus, 1758 - North America to N South America, Atlantic islands, Europe, N Africa (Tunisia) and W Africa (Mauritania, Senegal, erratically Nigeria), through Middle East and Black and Caspian Seas to Yenisey Valley; winters S of Tropic of Cancer.
minussensis Sushkin, 1925 - C Asia through Transbaikalia to N Mongolia and S Tibet; winters mainly N Indian Ocean.
tibetana Saunders, 1876 - W Mongolia S to Kashmir, Tibet and Sichuan, at high altitudes; winters mostly E Indian Ocean.
longipennis Nordmann, 1835 - NE Siberia S to NE China (C Heilongjiang to Inner Mongolia and Shanxi); winters SE Asia to Australia.