Sylvia Scop., Ann. i. Hist. Nat. p. 154 (1769). Type, S. cinerea (== communis) (Becht.).
The genus Sylvia contains sis Indian species, three of which are only subspecies of European forms. Sylvia differs from Hippolais in having a smaller bill and somewhat brighter colours, whilst in some species the two sexes differ in colour.
Sylvia has two moults in the year, unaccompanied by any change in the coloration of the plumage. All the species found in India are to some extent migratory.
In Sylvia the bill from the gape to the tip is shorter than the middle toe and claw; the three rictal bristles are weak and the supplementary bristles obsolete; the feathers of the forehead are decomposed and rough; the first primary is small and the second about equal to the sixth; the tarsus is short and stout and the tail is slightly graduated.
Key to Species.
A. First primary very small, not reaching to tips
of primary-coverts S. communis, p. 446.
B. First primary not so small, extending beyond tips of primary-coverts.
a. Crown of head black or dark brown………S. hortensis, p. 447.
b. Crown of head fawn-colour S. nana, p. 449.
c. Crown of head grey.
a1. Upper plumage greyish brown, darker on
crown S. althaea, p. 450.
b1 Upper plumage earthy-brown; more grey
on the crown S. curruca, p. 451.
c1. Upper plumage sandy-brown; more bluish
grey on the forehead S. minula, p. 451.