(2088) Sterna albifrons sinensis.
THE WHITE-SHAFTED TERNLET.
Sterna sinensis Gmelin, Syst. Nat., i, p. 608 (1789) (China) ; Blanf. & Oates, iv, p. 320 (part.).
Vernacular names. Muhudu lihiniya (Cing.); Kadal kuruvi (Tam.).
Description. The White-shafted Ternlet is separated from all the other Ternlets by the very shiny white shaft to the first primary as well as to the others; the bill is nearly as large as that of the European Ternlet but the upper tail-coverts are not always of so pure a white, though never so decided a grey or concolorous with the back as in the other Ternlets.
Colours of soft parts as in the other races.
Measurements. Wing 168 to 183 mm.; culmen 26 to 32 mm.; average 30 mm.
In Winter plumage, young and nestlings differ from the full Summer plumage as in the European Ternlet.
Distribution. The coasts of Ceylon, Burma and China; the Malay States and most of the islands of the Malay Archipelago.
Nidification. This Ternlet breeds on practically all the shores of Southern Asia from Ceylon to extreme East China and probably on the majority of the bigger islands. In China it also follows the courses of big rivers for about 100 miles inland, whilst in Ceylon it breeds on the sandy banks of the big tanks as well as on the sea-shore. No nest is made beyond the usual scratching in the sand. The colonies vary in size from a dozen or so to nearly a hundred, whilst the nesting-hollows are sometimes very close together, sometimes scattered over a considerable area. The eggs number one to three, generally two, the ground-colour varying from a pale buff, creamy-yellow or yellowish-stone to a deep buff or cafe-au-lait. The markings normally consist of primary blotches and spots of dark brown or reddish-brown with equally numerous secondary blotches of pale grey. These are scattered fairly freely over the whole egg but are more numerous at the larger end. One hundred eggs average 32.2 x 23.8 mm. : maxima 34.1 x 23.7 and 34.0 x 25.5 mm.; minima 29.3 x 23.0 and 31.2 X 22.5 mm. The nesting-season is from June to August in Ceylon and principally in June all over China.
Habits. Over its whole area this Tern is more a coastal form than a river bird, though in China it follows the course of the Yangtse for nearly 1,000 miles from its mouth. In Ceylon, although it breeds on the sandy shores of the tanks near the sea, it appears to keep almost entirely to the sea for fishing.