The genus Cisticola contains four Indian species of small size, which, on account of their complex plumage, have given much trouble to the ornithologist. They are now much better understood than they were a few years ago. The Indian species all have two complete moults a year, in the case of one giving rise to no alteration of colour worthy of note, but in the other three causing a very decided change of colour between the summer and the winter plumages, and accompanied in all four by a radical change in the form and Length of the tail. In three species the sexes are alike in the winter only, but in the fourth the sexes are alike throughout the year.
Sharpe has done excellent work in his Catalogue in bringing these troublesome birds into some order, but he has united three Indian species, an error of which I was myself guilty a few years ago. With the larger amount of material now available, however, in the Hume and Tweeddale collections, it is possible to arrive at safer conclusions.
The Fantail-Warblers are resident species in India, inhabiting grass and corn, but are in no degree aquatic in their Habits. They feed a good deal on the ground, and are not shy or difficult to observe.
I restrict the genus to those Warblers with a seasonal change of Length of tail, accompanied by a short first primary (less than half the Length of the second) and a very slender, sharp-pointed bill. These characters exclude Franklinia, which has a large first primary, a shorter and rounder wing, and a larger and blunt bill.
These Warblers have a moderate tail, almost short in summer, evenly rounded, and forming a perfect fan, whence the English name ; there are two short rictal bristles, no supplementary hairs, and the forehead is smooth.
Key to the Species.
a. Upper plumage streaked; the crown plain.
a1. Crown chestnut………………C. erythrocephala aest., p. 371.
b1. Crown pale yellow………………C. tytleri aest., p. 372. '
c1. Crown golden yellow………………C. volitans aest., p. 373.
b. Upper plumage streaked, including the crown.
d1. Tips to all the tail-feathers indistinct, dull rufous-white.
a2. Crown rufous with black streaks, the rufous preponderating.
a3. Back ashy, streaked with black
C. volitans seat. [hyem., p. 373.
b3. Back rufous, streaked with black………………C. erythrocephala aest. &
b2. Crown black, with narrow fulvous edges, the black preponderating much; a broad rufous collar round the hind neck………………C. tytleri rest. & hyem., [hyem., p. 371.p. 372.
e1. Tips to the lateral tail-feathers very broad and pure white………………C. cursitans, p. 374.