(483) Larvivora cyane.
The Siberian Blue Chat.
Motacilla cyane Pall., Reis. Russ. Reichs, iii, p. 697 (1776) (East Siberia).
Larvivora cyanea. Blanf. & Oates, i, p. 181.
Vernacular names. None recorded.
Description.— Adult male. Lores and a line under the eye black; cheeks, ear-coverts, sides of neck and whole upper plumage dark blue, the sides of the neck generally darker than elsewhere; tail and wing-quills brownish black, suffused with dark blue ; below white, the flanks washed with blue and the sides of the upper breast very deep indigo-blue.
Colours of soft parts. Iris brown; bill black in the breeding season; horny-brown above and fleshy-yellow or pale horny below in the non-breeding season; feet, legs and claws white to pale fleshy.
Measurements. Total length about 140 to 150 mm.; wing 71 to 81 mm.; tail 47 to 50 mm.; tarsus 26 mm.; culmen about 12 mm.
Adult female. Lores, forehead and sides of the head fulvous¬ rufous, mottled with darker; remainder of upper plumage olive-brown, tinged with russet on the rump and upper tail-coverts ; tail and wing-quills brown, edged with fulvous-rufous ; greater coverts brown, edged and tipped with rufous; below white, the breast-feathers edged with brown and tinged fulvous; flanks fulvous-brown.
Colours of soft parts. Iris dark brown ; bill above horny brown, mandible fleshy-yellow; feet white to fleshy or fleshy-yellow.
Measurements practically the same as the male.
Young male is like the female, but acquires a certain amount of blue on the lower back, rump, upper tail-coverts and tail at the first autumn moult, sometimes, also, patches of blue on the wing-coverts.
Nestlings are squamated on the lower plumage, spotted on the upper.
Distribution. Breeding in Eastern Siberia and Japan and possibly also in Mongolia and North-Eastern China. In winter migrating South to South China, the Indo-Chinese countries, Burma, Malay Peninsula, Borneo and probably most of the islands, Manipur and Assam. The label on the Pinwill specimen, " from Simla," is undoubtedly wrong, nor is there any further evidence in support of Seebohm's statement that it winters in North India.
Nidification. This beautiful little Short-wing breeds abundantly in Japan, making a cup-shaped nest of moss and leaves on the ground or in an old stump or a hole in a tree. The eggs number four or five and are in colour like rather deeply-coloured Hedge-Sparrow's eggs. The texture is very smooth and the surface has a distinct gloss. Thirty eggs average 19.6 x 14.5 mm. The breeding season is from early May to early July. Oates considered it possible that this Blue Chat bred in Burma, as he obtained a specimen on the 21st May. It has never again been procured in the breeding season and his bird was certainly only a late visitor.
Habits. The habits of the Blue Chats are the same as those of the other Short-wings. They are shy retiring birds, keeping much to forest and undergrowth, feeding entirely on the ground or close to it and are purely insectivorous. They all have a rather sweet but not very loud song, which they utter either on the ground or from some bush or low tree and in winter at all events, they have a habit of flirting their tails not unlike some of the true Chats.