Terns (Sternidae)

Gull-billed Tern (Gelochelidon nilotica) - HBW 3, p. 645

French: Sterne hansel German: Lachseeschwalbe Spanish: Pagaza Piconegra

Taxonomy: Sterna nilotica Gmelin, 1789, Egypt.
Along with Hydroprogne and Thalasseus, genus often merged with Sterna; behaviour intermediate between typical terns and crested terns, and unique combination of characters supports separate generic treatment. Listed as G. anglica in many older works. Proposed race affinis for birds of E Asia and SE China is not separable. Six subspecies recognized.

Subspecies and Distribution:

nilotica (Gmelin, 1789) - Europe S to Mauritania and Tunisia, and E through Middle East, Kazakhstan and Indian Subcontinent to NW China; winters from tropical Africa through Persian Gulf to India.
addenda Mathews, 1912 - Transbaikalia, Manchuria and E China (Fuzhou to Hainan); winters mainly SE Asia.
macrotarsa (Gould, 1837) - Australia.

See all 6 subspecies

nilotica (Gmelin, 1789) - Europe S to Mauritania and Tunisia, and E through Middle East, Kazakhstan and Indian Subcontinent to NW China; winters from tropical Africa through Persian Gulf to India.
addenda Mathews, 1912 - Transbaikalia, Manchuria and E China (Fuzhou to Hainan); winters mainly SE Asia.
macrotarsa (Gould, 1837) - Australia.
aranea (Wilson, 1814) - New Jersey (rarely New York) S to Texas, Cuba, Bahamas and Puerto Rico, and sparsely along Mexican coast to Yucatán; winters along Central American coasts and S to Brazil and Peru.
vanrossemi Bancroft, 1929 - California (coastal plain and Salton Sea) to N Baja California and Sinaloa (and probably S to Gulf of Tehuantepec), with isolated breeding recorded in Alaska (Copper R Delta); winters S to Ecuador.
groenvoldi Mathews, 1912 - coast and river valleys from French Guiana (Cayenne) to NE Argentina (Buenos Aires); Ecuador and N Peru breeders may be this race or vanrossemi, or an undescribed race.