THE AQUATIC WARBLER. 349 



MIGRATIONS. British Isles. Early arrivals of summer -residents 

 second week April (early date 2nd), main arrival begins last week 

 April (first week May in some years) and becomes merged in move- 

 ments of passage-migrants, that last from first week May to first 

 week June and take place by both east and west coast routes 

 (Scillies to Solway and Channel to Forth) and northern isles. 

 Departure of summer-residents begins end July (early date Channel 

 Islands Lt. 16th), heaviest period latter half Aug. and first half 

 Sept. Becomes merged into movements of passage-migrants that 

 begin first week Aug. and last to end Sept. both east and west coast 

 routes (as spring) being used. (Late dates St. Catherine's Lt. (Isle 

 of Wight), Oct. 2 ; Eddystone Lt. (Cornwall), Oct. 3 ; Skerries Lt. 

 (Anglesey), Oct. 6.) 



DISTRIBUTION. Abroad. From about lat. 70 north in Sweden, 

 the Murman Coast and Archangel, Ob and Yenisei throughout 

 western Siberia and Altai Mountains, Russia and Europe, but rare 

 or absent from Spain and Greece, wintering in Asia Minor and 

 Africa. Accidental Madeira. 



ACROCEPHALUS AQUATICUS 



147. Acrocephalus aquaticus (Gm.) THE AQUATIC 

 WARBLER. 



MOTACILLA AQTJATICA Gmelin, Syst. Nat., i, ii, p. 953 (1789 No locality 

 given. Ex Scopoli, who described birds from Carniola or Venetia). 

 Acrocephalus aquaticus (J. F. Gmelin), Yarrell, i, p. 380 ; Saunders, p. 87 . 



DESCRIPTION. Adult male, and female. Winter. Broad line down 

 centre of crown pale yellow-buff, fore-head tawny-buff, sides of 

 crown brown-black feathers narrowly edged buff ; nape buff 

 narrowly streaked brown to brown-black ; mantle and scapulars 

 more tawny-buff or pale tawny-brown and with broader and very 

 prominent brown-black streaks ; rump same but with narrower 

 streaks ; upper tail-coverts tawny-brown with dark brown shaft- 

 streaks ; broad and distinct stripe from nostrils over and behind 

 eye pale yellow-buff ; lores creamy-white ; ear-coverts pale yellow- 

 brown streaked brown-black on upper portion ; chin and centre of 

 belly white to yellowish-white ; sides of throat, breast, flanks and 

 under tail-coverts pale yellow-buff to pale tawny-buff with varying 

 number of very narrow dark brown streaks on base of throat, 

 breast and flanks (but often these streaks are absent) ; under tail- 

 coverts sometimes with brown shaft-streaks ; axillaries and under 

 wing-coverts white with dusky centres ; tail-feathers : most of 

 outer webs and edges of inner webs pale brown or tawny-brown, 

 centres dark brown ; wing-feathers dark brown narrowly edged on 

 inner webs whitish and on outer webs pale brown, tips whitish- 

 brown, innermost secondaries black-brown broadly edged and 

 tipped yellowish or tawny-buff to pale tawny-brown ; primary- 



