Key to Subspecies.
A. Paler below, more fulvous, not rufous.
a General tone of upper plumage pale earthy- brown ………P. i. inornata, p. 534.
b. Above decidedly richer and browner……………………P. i. jerdoni, p. 535.
c. Above dark earthy-brown, tinged grey …………………P. i. burmanica,
B. Darker below, fulvous strongly tinged with rufous on flanks,
thighs and vent ……………………………PA. blanfordi, p. 537. [p. 536.
Prinia inornati herberti is almost sure to be found in the low-lying swampy portions of Eastern Tenasserim. It is a much deeper-coloured bird than any of the above races and has no fulvous, or rufous tinge on the upper plumage.
The eggs of this species form one of the most curious instances of variation according to the geographical distribution of the subspecies that I know of. The eggs of P. i. jerdoni from Ceylon and South India are a brilliant blue, spotted and streaked with deep red, purplish black or black. In Northern India the eggs laid are decidedly a less brilliant blue and the markings are less deep-coloured, more often reddish brown than nearly black. In Oudh, we have these normal blue eggs over the greater part of the Province but in one small area round about Gonda the birds generally lay white eggs with bold blood-red and blackish spots and blotches. In Assam and Burma, P. L burmanica lays a duller blue egg, often tinted with pink, whilst in the South of Burma P. i. blanfordi lays a dull pinkish egg with reddish blotches and scrawls. Finally, in Siam, P. i. herberti lays the most beautiful pink eggs with great blotches and lines of blood-red, purplish red or almost black. The gradation from brilliant blue to the other extreme of brilliant pink is perfect but the cause for the variation is still obscure.
In each area an occasional aberrant clutch of eggs may be found similar to the common type in one of the other areas.