28 THE WARBLERS 



4. Nest and Eggs. Nesting site : variable according to locality. Thus on 

 the moorlands it is placed among long heather, on commons often low down 

 in gorse bushes ; in osier beds, plantations with heavy undergrowth and rank 

 hedge bottoms or thickets, it is hidden among the rank grass tussocks, while 

 in the Broad district it breeds close to the water among the thick growth of water 

 plants as well as in open fairly dry places. It is, however, always an exceed- 

 ingly difficult nest to find, although sometimes discovered by accident, and is 

 generally quite invisible from above and approached from the side by the birds. 

 It is composed of stalks and grasses, with a little moss or a few leaves in the 

 foundation. (PI. xxn.) What share is taken by the two sexes in building is not 

 recorded. Eggs, usually 6 in number, sometimes only 5, speckled thickly over 

 the whole surface with fine red-brown spots, which occasionally form a zone and in 

 rare instances are replaced by bold blotches on a creamy white ground. (PI. D.) 

 Average size of 100 eggs, -69 x -53 in. [17-5 x 13-5 mm.]. Laying usually takes place 

 during the last fortnight of May, occasionally about the middle of the month, and 

 incubation, which lasts 16 days according to H. E. Howard, is performed by the hen, 

 who is a very close sitter. One brood is usually reared, but there is evidence that 

 in some cases a second is also produced. [F. c. B. J.] 



5. Food. The species is entirely insectivorous. The young are fed by both 

 parents largely on small caterpillars when a few days old ; but to begin with, the 

 food supplied is very minute probably aphides and tiny spiders. [E. L. T.] 



6. Song Period. From about the end of April till the beginning of 

 August. [E. L. T.] 



The following species and subspecies are described in the supplementary chapter on 

 " Rare Birds " : 



Sardinian-warbler, Sylvia melanocephala (Gmelin). 

 Orphean- warbler, Sylvia orphea Temminck. 1 

 Barred-warbler, Sylvia nisoria (Bechstein). 

 Subalpine-warbler, Sylvia subalpina (Temminck). 

 Yellow-browed warbler, Phylloscopus superciliosus (Gmelin). 

 Pallas' willow-warbler, Phylloscopus proregulus (Pallas). 

 Greenish willow-warbler, Phylloscopus viridanus Blyth. 

 Siberian-chiffchaff, Phylloscopus collybita tristis Blyth. 



1 By the rule of strict priority the name of S. hortensis (which has generally been applied 

 to the garden-warbler) belongs to this species. 



