(1230) Mirafra javanica williamsoni.
The Siam: Singing Bush-Lark.
Mirafra cantillans williamsoni Stuart Baker, Bull. B.O.C., xxxvi, p. 9,1915 (Bangkok).
Vernacular names. Nok-a-chap fon lepsan (Siam).
Description. Differs from M. c. cantillans in being very dark above, the paler margins to the feathers being narrower and more rufous; the rufous of the wings is much deeper; below, the plumage is duller, less fulvous and more oily fulvous-grey.
In the present bird the dark centres to the feathers of the upper plumage dominate the general tone, whilst in cantillans the rufous margins and pale edges do so.
Colours of soft parts as in M. c. cantillans.
Measurements. Wing 70 to 77 mm.; tail 39 to 48 mm.; tarsus 20 to 21 mm.: culmen about 12 to 13 mm.
Distribution. Siam. I have also received skins with nests and eggs from East of Myawaddy, Eastern Tenasserim, which are referable to this race.
Nidification. Similar to that of the Indian Singing Bush-Lark but the nest is generally placed on the ground in the dry rice-fields in among the grass which grows up here and there after the rice is cut. The dome of the nest is made, like that of the preceding bird, partly from material collected by the bird and partly from the surrounding grass. The eggs, which number three or four, are like those of its Indian cousin but as a whole are much more deeply marked and have a far higher gloss, whilst, as might be expected, they are much smaller. Fifty eggs average 19.7x 14.6 mm.: maxima 20.7 X 15.0 and 20.6 x 15.3 mm.; minima 17.8 x 14.3 and 18.0 x 13.9 mm.
The principal breeding-season is from the middle of May to the end of July.
Habits. Similar to those of the preceding bird but it seems to be even more feeble both in flight and voice, though Herbert says that its song is sweet. It keeps in Siam almost entirely to rice-fields in the dry season, resorting to grass, both short and long, during the rainy season. Herbert remarks on the curious manner in which this Lark, when flushed in long grass, flies a short distance and then hurls itself down headlong into it just as the Button-Quails do.