Order LARIFORMES 
No. 124. 
Family LARIDJS. 
HYDROOHELIDON LEUCOPTERA GRISEA. 
EASTERN WHITE-WINGED TERN. 
(Plate 102.)* 
Sterna geisea Horsfield, Trans. Linn. Soc. (Lond.), Vol. XIII., p. 199, 1821 ; Java. 
Sterna grisea Horsfield, Trans. Linn. Soc. (Lond.), Vol. XIII., p. 199, 1821. 
HydrocJielidon leucoptera Gould, Proc. Zool. Soc. (Lond.) 1866, p. 218 ; Hutton, Cat. Birds 
New Zeal., p. 43, 1871 ; Buller, Birds New Zeal., p. 287, 1873 ; id., ib., 2nd ed., 
Vol. II,, p. 77, 1888 ; Saunders, Oat. Birds Brit. Mus., Vol. XXV., p. 6, 1896 
(pars) ; Hall, Key Birds Austr., p. 87, 1899 ; Campbell, Nests and Eggs Austr. 
Birds, p. 828, 1901 ; Buller, Suppl. Birds New Zeal,, Vol. I., p. 157, 1905 ; Hall, 
Key Birds Austr., p. 87, 1906 ; Mathews, Handl. Birds Austral., p. 20, 1908. 
Hydrochelidon leucoptera grisea Mathews, Nov. Zool., Vol. XVIII., p. 207, 1912. 
Distribution. North Australia (winter-visitor) ; ? New Zealand (accidental) ; Java 
(winter- visitor) ; China (breeding). 
Adult male in breeding-plumage. Head and neck all round glossy-black like the breast, 
abdomen, sides of body, axillaries, and under wing-coverts ; spot below the eye 
white ; back and scapulars dull slaty-black ; lesser wing-coverts white ; bastard- 
wing and primary-coverts pale silvery-grey, becoming darker grey on the median 
and greater coverts, the innermost greater-series dark slate-grey ; primary-quills 
silvery-grey along the outer webs, inner webs dark brown near the shafts with 
the remainder white ; inner primaries almost entirely silvery-grey ; secondaries 
slate-grey, becoming much darker on the innermost feathers ; upper and under 
tail-coverts, as also the tail, white ; bill red ; iris brown ; feet red. Total length 
221 mm. ; cuhnen 24, wing 217, tail 73, tarsus 21. 
Adult female in breeding-plumage. Similar to the adult male, but duller black on the back, 
breast, abdomen, sides of body, and under wing-coverts, the latter inclining to 
white on the greater series ; the tail shows a distinct grey wash, while the measure- 
ments are distinctly smaller. 
Adult in winter-plumage. The forehead, back of the neck, all the under surface and under 
wing-coverts white ; back of the head and nape dark brown with whitish tips ; the 
feathers of the upper-back are dark brownish-grey ; the tips fighter, and their 
bases white ; the back fighter ; the rump and upper tail-coverts fight grey ; the 
tail-feathers are grey, the outer whitish on the inner webs ; there is a distinctly 
defined black spot in front of the eye, and the ear-coverts form a dark brown patch ; 
the primaries are all worn duU brown, while the scapulars and median wing-coverts 
retain their grey colour. 
* The Plate is lettered Hydrochelidon leucoptera. 
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