WILLOW-WARBLER. 185 



damage in this way. In April and May the male chases the 

 female through the trees, flying very swiftly, the lighter under 

 pans flashing as they turn and dodge. In display he will droop 

 his wings and puff out his feathers, or clinging to a twig or 

 stem, gently fan his open wings, frequently one wing at a time ; 

 during this performance he usually sings, and then with tail 

 raised and expanded and with quivering wings slightly uplifted 

 floats obliquely towards his mate. I have known a pair begin 

 to build three days after this show, and I agree with Miss 

 Turner that the male certainly at times helps in construction. 



The nest is partly domed (Plate ^']) and usually built on 

 the ground, distinguishing it from the normal nest of the 

 Chiffchaff, which is above the ground ; but in both species 

 there is individual variation, and a Willow-Wren's nest at a 

 height above ground is not uncommon. Grass is the usual 

 material, but moss and dead bracken are sometimes added ; 

 a nest so constructed is hidden in the winter litter before the 

 " croziers " have unfolded, and when the fronds unfold it is 

 almost impossible to find unless our footfall scares the sitting 

 bird. When thus disturbed the bird usually flies straight ofl", 

 but occasionally feigns injury, but I have known one fly up into 

 a tree and at once begin to sing. As a rule, long before 

 the nest is reached, one or both birds begin plaintive notes 

 of anxiety. The six to eight eggs (Plate 65) are laid in May, 

 and it is thought that second broods are rare, late nests being 

 the result of an accident to the first clutch ; they are white 

 blotched with red, rather like the eggs of tits, and with paler 

 markings than those of the Chiflchaff. Emigration begins 

 in August, but the majority of the birds leave during September. 

 The WiUow-Wren has been recorded as wintering in England, 

 but some of these winterers may have been Chiffchaffs. 



The upper parts in spring are yellowish olive, yellowest on 

 the eye-stripe and rump ; the wings are browner, the feathers 

 margined with greenish yellow. The under parts are yellowish 



