HYDROCHELIDON.
Marsh Terns; tail less deeply forked than in "Sterna," and toes longer and only half webbed; affect inland marshes more than coast; nest in marshes on ground or on floating herbage; eggs 3, ochreous clay or olivaceous, closely blotched and spotted with purplish grey and blackish brown.
Hydrochelidon nigra nigra (L.). BLACK TERN. Fr. Guifette noire ; Ger. Schwarze Seeschwalbe ; Ital. Mignattino ; Swed. Svart-Tarna.
6 summer. Above grey slate ; crown, face and nape black ; beneath slaty black, under tail coverts white, under wing coverts and axillaries pale grey. Bill black. Legs and feet reddish brown. In winter : above paler, forehead white, crown browner ; beneath greyish white. 9 like d but underparts in summer slaty grey. Wing d 9 20S-222. Tarsus 15-17. Bill 24-28. Young : mottled with brown and white with some black on sides of chest. Bill brownish black. Legs and feet brownish flesh.
Preeds.—From S. Sweden, Gothland and Oland Islands and Russia from L. Ladoga and Penn south throughout Europe to S. Spain, Balearic Islands, N. Italy, Rumania, Bulgaria, and S. Russia, regularly in Denmark and Holland, rare in France ; also in \V. Asia. Migrates ; occurs British Isles on passage, and N. Africa (Morocco to Egypt). Winters in tropical Africa.
Hydrochelidon leucoptera (Temminck). WHITE WINGED BLACK TERN.
cc 9 summer. Head, neck, back, scapulars, and underparts black ; lesser wing coverts and edge of wing white, greater wing coverts and shorter primaries pale grey ; upper tail coverts, vent, under tail coverts, and tail white (in 9 tail grey except base and outer feathers, which are white), under wing coverts and axillaries black. Bill, legs and feet red. Iris dark brown. In winter : above grey, forehead, hind collar, and underparts white ; crown mottled black ; tail grey above, paler below, under wing coverts and axillaries white. Wing d 208-225, 9 202
2 15. Tarsus 18-22. Bill 21-25. Young like adult in winter, but crown, hack, and scapulars brown or grey mottled with brown.
Brectis.—Russia north to Pskov and Esthonia, Galicia, Hungary ; possibly S. Italy, Sicily, Egypt, and Algeria ; and widely in N. Asia. Migrates ; occurs occasionally in W. Europe on passage, even as far west as Britain ; commoner in Morocco, Algeria, and Tunis. Winters in Africa south to Cape Colony, and from S. Asia to Australia.
Hydrochelidon leucopareia leucopareia (Temminck). WHISKERED TERN. Fr. Hirondelle de mer moustas ; Ger. Weissbartige Seeschwalbe ; //a/. Mignattino bigio.
9 summer. Crown and nape black, upper parts slate grey ; beneath, face and chin white, white streak from gape to nape, throat and breast pale slate, abdomen sooty black, under tail coverts, under wing coverts and axillaries white. Bill red. Legs and feet vermilion. In winter crown and nape are white streaked with black, and underparts white. Wing 6' ? 234-24o. Tarsus 22-24. Bill 29-31. Young are like winter adults, but crown is brown freckled with white, scapulars and secondaries mottled, with dark centres and buff margins. Bill and legs brown.
Breeds.—Portugal, Spain, S. France (Camargue), Hungary, Danube Valley, Dobrudscha, S. Russia north to S. Poland and Volga Valley ; N. Africa (Morocco to Egypt) ; also W. Asia. Migrates. Winters in Africa. Of occasional occurrence in N. Central and N. Western Europe. Casual in British Isles.