1503. Sterna seena.
The Indian River-Tern.
Sterna seena, Sykes, P. Z. S. 1832, p. 171; Hume & Oates, S. F. iii, p. 193 ; Butler, S. F. iv, p. 32; Fairbank, ibid. p. 264; Inglis, S. F. v, p. 47; Hume & Dav. S. F. vi, p. 492; Anders. Yunnan Exped., Aves, p. 693 ; Ball, S. F. vii, p. 233 ; Cripps, ibid. p. 314; Hume, Cat. no. 985 ; Scully, S. F. viii, p. 364; Legge, Birds Ceyl. p. 1003 ; Butler, S. F. ix, p. 440 ; Reid, S. F. x, p. 86 ; Davidson, ibid. p. 326; Oates, B. B. ii, p. 423; Barnes, Birds Bom. p. 429 ; id. Jour. Bom. N. H. Soc. i, p. 61 ; vi. p. 294; Hume, S. F. xi, p. 350; Oates in Humes N. & E. 2nd ed. iii, p. 308. Sterna aurantia, Gray, in Hardw. Ill. Ind. Zool. i, pl. 69, fig. 2 (1832); Hume, S. F. i, p. 281. Seena aurantia, Blyth, Cat. p. 291; Jerdon, B. I. iii, p. 838; Godw.-Aust. J. A. S. B. xxxix, pt. 2, p, 275; Hayes Lloyd, Ibis, 1S73, p. 421 ; Blyth & Wald. Birds Burm. p. 163 ; Wardl.-Rams. Ibis, 1877, p. 472; Saunders, Cat. B. St. xxv, p. 37.
The Large River- Tern, Jerdon.
Coloration. The whole head to considerably below the eyes and including the nape black glossed with dark green, a white spot under each eye; rest of upper parts French grey, paling to pearl-grey on the rump and tail; chin and a streak on each cheek bordering the black cap, together with the under tail-coverts, white; remainder of lower surface, inclusive of wing-lining, delicate pale grey.
After the moult, which does not occur till about December, the forehead is white and the crown dull grey, then black streaks appear and the black cap is generally assumed by February. Young birds have the feathers of the upper parts dull grey, with an inner brown and an outer buff margin.
Bill bright deep yellow; irides brown ; legs red (Jerdon). The bill and legs are duller coloured and the tip of the bill dusky in autumn.
Length 15 to 18 ; tail 6 to 9-5, depth of fork 5 to 6; wing 11; tarsus .8 ; bill from gape 2.3.
Distribution. Throughout India and Burma on all large rivers, less common in the south of the Peninsula, and of doubtful occur¬rence in Ceylon. This Tern is also found throughout the Malay Peninsula as far as Singapore.
Habits, &c. Though essentially a river Tern, occurring singly or in small parties about rivers and estuaries, this handsome Indian Tern is often met. with beating over tanks and even marshes, especially if they are in the neighbourhood of rivers. It breeds in March, April, and May, and lays 3 (sometimes 4) eggs in a small unlined depression on a sandbank. Hundreds of nests sometimes occurs on one sandbank, and other Terns, Skimmers, and Glareola breed about the same time in similar places. The eggs vary from pale greenish grey to buff, spotted and blotched in the usual manner with dark brown and pale inky purple, and they measure on an average 1.65 by 1.25. The place where these or any Terns are breeding may generally be recognized by the way in which the birds wheel about overhead with their peculiar cry when anyone is near their nests.