340 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



long oval, lateral black spots at base of tongue ; externally flanges 

 pale yellow. 



Juvenile. — Upper-parts as adult but more rusty-brown, the 

 rusty colour being especially noticeable on rump, wing-coverts 

 and edges of innermost secondaries ; chin and throat dusky-buff 

 (not white) ; breast, sides and flanks more dusky, not so clear 

 a buff as in adult ; narrow rusty tips to tail-feathers. 



First winter. — Like adults and very difficult to distinguish, 

 but usually more rusty-brown on upper-parts and also on edges 

 of innermost secondaries and greater coverts ; under-parts a shade 

 darker buff, but these differences disappear by abrasion. The 

 juvenile body -plumage and apparently lesser and median wing- 

 coverts are moulted July-Sept. 



Measurements and structure. — ^ wing 62-70 mm., tail 49-55, 

 tarsus 23-24, bill from skull 15-17. $ wing 62-68. Primaries ; 

 1st equal to, or 1-2 mm. shorter than primary-coverts, 3rd longest, 

 2nd 1 .5-3 shorter (often equal to, sometimes shorter than and more 

 rarely longer than 4th, exceptionally equal to 5th) 4th 1-3 shorter, 

 5th 3-5 shorter, 6th 5-8 shorter ; 3rd emarginated outer web, very 

 rarely an indication of emargination on 4th ; 2nd with a notch on 

 inner web falling usually between tip of 8th primary and tips of 

 secondaries but very rarely as high as tip of 7th primary. Outer tail- 

 feathers 5-8 mm. shorter than central. Tips of tail-feathers in- 

 clined to be pointed. BiU rather wide and flat at base, compressed 

 and thin at tip. OtherAvise as ^. a. arundinaceus. 



Soft parts. — Bill : upper-mandible dark brown, under-mandible 

 pale flesh, sometimes yellowish ; inside mouth orange ; legs and 

 feet brown ; iris pale brown. 



Characters and allied forms. — A. s. macronyx (Transcaspia, 

 Turkestan, Persia) is considerably paler and less reddish-brown on 

 upper -parts and paler (less buff) on under-parts. For differences 

 of A. pahistris and A. dumetorum see " Description " and " Measure- 

 ments and structure " under those species. 



Field -characters. — Seldom leaves cover of reed-beds, or osier- 

 beds and riverside bushes which to a lesser extent constitute its 

 haunts, among which it moves about with restless activity. Uniform 

 brown upper -parts tinged with chestnut, nearly white under-parts, 

 and obscure pale eye-stripe render it almost indistinguishable in 

 field from rarer and more local Marsh-Warbler, which however 

 frequents swampy thickets of meadowsweet and rank herbage rather 

 than reed-beds. Song, uttered by day and night, is a babbling 

 chatter, " churra, churra, churra," followed by a variety of rapid 

 notes, far less melodious and imitative than song of Marsh-Warbler 

 and lacking harsh notes of Sedge -Warbler. Call-note, " turr." 

 Alarm-note a low croak. 



Breeding-habits. — Generally breeds in reeds on edge of stream 



