IN JERDON OR STRAY FEATHERS. 397 



It is only on close examination that the difference in the 

 colours of the margins and centres of the feathers of the 

 head, back, and other parts is observed ; looked at from the 

 distance of a couple of feet, these parts appear of a uniform 

 brown, less rufous in tone than that of the same parts of 

 Acrocephalus agricohis, to which the bird, after its autumnal 

 moult, presents a general resemblance in colouring (though of 

 course differing, as already noticed, in structure), but still, in 

 most specimens, with a certain shade of rufous. The amount 

 of this of course varies, some specimens being greyer and 

 some more rufous. 



At this season of the year it would be impossible (setting 

 aside structural differences) to mistake this species for Hy- 

 polais rama ; it is altogether a darker bird, conspicuously so 

 when on the wing ; it never has the uniformly mouse or grey 

 brown of that species ; its habits, too, are widely different, 

 quite those of an Acrocephalus (like A. dumetorum), frequenting 

 thick crops, from which it is only flushed with great difficulty, 

 dropping again after a short flight. H. rama, on the other 

 hand, is rarely found in, and never sticks close to thick ground 

 covert, but affects trees and bushes, more especially the babool 

 (Acacia arabica). 



The notes are entirely those of an Acrocephalus, most resem- 

 bling those of A. dumetorum, but perhaps rather more saxico- 

 line in their character. In the spring and summer the whole 

 upper surface of the bird becomes paler, and what some would 

 describe as more rufous, others as more sandy, while the lower 

 parts lose a great deal of their warm buffy tint; the remiges and 

 rectrices also fare similarly. In this stage it might easily be 

 mistaken by a casual observer for a small specimen of H. rama; 

 but its upper surface is always somewhat more rufous in tone 

 than that of the latter. 



Comparing specimens of our bird freshly moulted, at the 

 close of September, with specimens of H. rama in similar plum- 

 age, the difference (independent of structure and habits) is 

 very noticeable. H. rama, even in its fresh feathers, is a 

 smooth, light grey-brown bird, very uniform in colour, and 

 with the lower parts quite devoid of the ruddy buff tint of 

 caligata. The feet, too, of H. rama are of a greenish blue orev, 

 darker about the foot (the soles excepted), while the feet of 

 caligata are of a warmer flesh colour ; indeed, in the colour 

 of the feet and tarsi the birds differ conspicuously.— Hume, 

 "Ibis;' 1870, 182. 



51 



