NON-INDIGENOUS BRITISH BIRDS. 67 



Family TURDID^. Genus Acrocephalus. 



Sub-family SYLVIIN^.. 



AQUATIC WARBLER. 



Acrocephalus aquaticus {Gj?ielin). 



(British : Very rare abnormal autumn migrant.) 



Single Brooded. Laying season, latter half of May and early 



June. 



Breeding area : South-western PaLearctic region. 

 The Aquatic Warbler has a somewhat restricted breeding 

 range, being for the most part confined to Central 

 Europe. It breeds in Denmark, Germany, the Nether- 

 lands, France, Italy (including Sardinia and Sicily), 

 Austria, and Central Russia, as far east as the Southern 

 Urals. South of the Mediterranean it is said to breed 

 sparingly in Algeria and Tunis, but its distribution is 

 very imperfectly defined. 



Breeding habits : The habits of the Aquatic 

 Warbler are very similar to those of the Sedge Warbler, 

 and the kind of localities it frequents are very much the 

 same. It reaches its more northern summer haunts 

 during the third week in April. Its favourite haunts 

 are swampy localities, the vegetation on the banks 

 of rivers and ponds ; ditches which are almost choked 

 with aquatic herbage, brambles, and briars ; thickets 

 of willows and osier beds. It is a shy and secretive 

 species, keeping much to the cover of the vegetation. 

 It pairs soon after its arrival, but very often nesting does 

 not commence for several weeks after that event. The 

 nest is open and cup-shaped, and though never exactly 

 upon the ground is often built a few inches above it, 

 and rarely more than a foot or eighteen inches from it. 

 It is said to be suspended between the stalks of plants 



