The genus Orthotomus contains three Indian species of rather bright plumage, approaching in this respect Cryptolopha, Abrornis, Tickellia, and Phyllergates. From the first of these it differs by the absence of all hairs on the forehead and over the nostrils, and from the other three by the possession of twelve tail-feathers.
The Tailor-birds are remarkable for the skill they display in the construction of their nests. Wherever they occur they are tolerably common, and in every case they are resident, without the slightest tendency to migrate or even to move locally. The sexes differ slightly in each species ; and the spring moult is apparently only a partial one, resulting in no change of colour. One species, however, is notable for the acquisition in the spring, by the male alone, of a tail of extraordinary Length : in the autumn the ordinary short tail is resumed. The Tailor-birds are furnished with certain long soft hairs springing from the nape.
In this genus the bill is as long as the head, broad and rather flat. There are a few rictal bristles on each side, but no supplementary hairs, and the forehead is very smooth and flat; the wing is very short and rounded, the first primary large and the next two graduated; the tail has twelve feathers and is much graduated; the tarsus is long, and these birds move on the ground with ease.
Key to the Species.
a. Upper body-plumage yellowish green.
a1. Axillaries, under wing-coverts, edge of wing, and under tail-coverts white, merely tinged with yellow…………………O. sutorius, p. 366.
b1. The same parts bright yellow…………………O. atrigularis, p. 368.
b. Upper body-plumage ashy…………………O. ruficeps, p. 368.