HYDROCIIELIDON. 



301 



Order GAVL^. 

 Family LARID^. 



Sub-family STERNIN^. 

 Oen-VLS IZ:"2-IDiSOOI=CEXjIIDOlNr, Boie. 



Hydrochelidon hybrida. 



MARSH TEKN. 

 Sti'riia Jii/hriila, Pallas, Zoogr., Rosso-Asiat., Tom. II., p. 338 (1811). 

 Hi/drochelidon jhmialilis, Gould, Bds. Austr., fol. Vol. VII., pi. 31 (18'18). 

 Hydrochelidon leucopareia, Gould, Handbk. Bds. Austr., Vol. II., p. -106 (I8G5). 

 Hydrochelidon hi/brida, Saunders, Cat. Bds. Brit. Mus., Vol. XXV., p. 10 (1896J ; Sliarpe Haiid-I. 

 Bds., Vol. I., p. 133 (1899). 



Adult .m.^le. — General colour above, including the icings, delicate grey ; inner webs and tips 

 of the tivo outer primaries blackish-grey, their bases broadly margined with white, the remainder 

 similar bnt ivilh the white decreasing on the innermost primaries ; onter webs of the outer secondaries 

 tchite, liglil bhickish grey near (lie shaft : the innermost secuudaries like the back; tail-feathers light 

 grey, the lateral feathers ivhite ; forehead, crown and nape black ; sides of face and nape, the chin and 

 upjier throat pure white : lower throat and fore-neck delicate grey and gradually passing into dark 

 slafi/grey on the lower breast and blackish-grey on the abdomen and flanks ; under tail-coverts white ; 

 bill blood-red ; legs and feet blood-red ; iris black. Total length in the flesh 10-5 inches, wing 9, lateral 

 tail feathers 3'4, bill 1-2, tarsus O'O. 



Adult female. — The sexes are alike in plnmage. 



Dish'ibidioii. — North-western Australia, Queensland, New South Wales, Victoria, South 

 Australia, Central Australia, Western Australia. 



XCfiT NLIKE the preceding Order Limicolfe, of which only about one half are found breeding 

 V_^ in Australia, the Terns and Gulls inhabiting Australia and Tasmania, and constituting 

 portion of the Order Gaviae, are all found breeding within the limits of the States ; the range of 

 several species of the Terns also e.Ktends to other countries. Terns or Sea-Swallows chiefly 

 frequent the headlands, bays, estuaries of the coast, and adjacent islands, on which they breed ; 

 Hydi-ochclidon liyhrida and Gelochclidon macrotarsa, are, however, far more abundant, and breed 

 inland. Terns pass most of their time on the wing, and although good divers are poor 

 swimmers, and when on land seldom use their locomotory powers. 



The Marsh Tern is a visitant to many inland localities of the Australian States, more 

 particularly after an abundant rainfall, when the tanks, water-holes and lakes are full of 

 water, and they may be absent again for many years, for they seem to roam about the country 

 from one favourite feeding ground, or breeding-place, to another, just as occasion requires. 

 Not only is it an inhabitant, at one season or another, of all the Australian States, but according 

 to the late Mr. Howard Saunders, in the " Catalogue of Birds in the British Museum," it is 

 found throughout Africa, and occurs in Central and Southern Europe in summer, eastward 

 throughout temperate and warmer Asia to China, and southwards by Malaysia to Australia. 



In New South Wales it is more abundantly distributed in the vicinity of the marshes, lagoons 

 and inland lakes, covered with a low and stunted vegetation, in the western portions of the State. 



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