350 BRITISH BIRDS. 



Genus ACROCEPHALUS. 



The Reed-Warblers were included by Linnaeus in his extensive genus 

 Motacilla, and were afterwards removed by Scopoli, along with the other 

 Warblers, into his genus Sylvia. The elder Naumann was the first to 

 subdivide Scopoli's genus; and in 1811, in the Supplement to his ' Natur- 

 geschichte der Land- und Wasser-Vogel des nordlichen Deutschlands und 

 angranzender Lander/ p. 199, he founded the genus Acrocephalus for the 

 Reed- War biers, and placed A. turdoides first on his list. This bird, which 

 is a fairly representative example of the genus, may therefore be accepted 

 as the type. 



The Reed-Warblers are a well-marked group of birds, distinguished by 

 the possession of a very minute bastard primary and a moderately rounded 

 tail. The bastard primary is so minute that in adult birds it does not 

 usually extend as far as the primary-coverts ; but in birds of the year, and 

 in one or two species slightly aberrant in this respect, it is usually some- 

 what longer, occasionally extending beyond them. The bill is typically 

 large, depressed and broad at the base, with moderately developed rictal 

 bristles. In two of the species the bill is somewhat aberrant, being as 

 slender as in the genus Locustella. These two species are also distinguished 

 by a different style of colouring, each feather on the head and back being 

 darker in the centre. The existence of two other intermediate species, 

 however, makes it advisable not to separate them more than sub- 

 generically from the typical Acrocephali, of which they form the Cala- 

 modine group. 



The tail is more rounded than in Hypolais, and much more so than in 

 Phylloscopus, but not so much so as in Locustella, the outside tail-feathers 

 being longer than the under tail-coverts. The general colour of the 

 plumage is a more or less uniform brown, sometimes olive-brown, some- 

 times russet-brown, gradually fading, as the plumage becomes abraded, 

 into a neutral brown or dust-brown, not inaptly described as museum- 

 colour. 



The Reed- Warblers, as their name implies, frequent marshy districts, 

 reed-beds, and the dense vegetation on the banks of still waters. They are 

 possessed of considerable powers of song. They build well-made open 

 nests, sometimes suspended over the water, attached to reeds or twigs, and 

 sometimes in the bushes ; and their eggs are from four to six in number. 

 Their food is principally insects. 



The breeding-range of these Warblers extends over the whole of the 

 Central and Southern Palsearctic Region ; and one species is found as far 



