70 THE NESTS AND EGGS OF BRITISH BIRDS. 



we frequently find a certain spot tenanted year by year. 

 The nest, made towards the end of April, is invariably 

 placed on the ground, and generally well concealed, 

 either by a tuft of herbage, a projecting stone, or a clod 

 of earth. It is made of a variety of materials, those 

 being selected that are most readily obtainable. As a 

 rule, dry coarse grass, roots, and moss form the outside ; 

 the inside is somewhat neatly lined with finer roots and 

 feathers, hair and fur, according to circumstances. The 

 nest is rather loosely put together. 



Range of egg colouration and measurement: 

 The eo-o-s of the Yellow Wagtail are from four to six in 

 number. They are grayish-white in ground colour (ex- 

 ceptionally suffused with a rosy tinge), mottled and 

 speckled with pale yellowish-brown or olive-brown, and 

 occasionally streaked with blackish-brown on the larger 

 end. The colouring matter is generally so thickly dis- 

 tributed over the entire surface of the egg as to hide all 

 or nearly all the pale ground colour. Average measure- 

 ment, 78 inch in length, by -56 inch in breadth. Incuba- 

 tion, performed chiefly by the female, lasts about fourteen 

 days. 



Diagnostic characters : As previously remarked, 

 the eggs of the Yellow Wagtail are often absolutely 

 indistinguishable from those of the Blue-headed and 

 Gray Wagtails, and from certain varieties of those of 

 the Sedge Warbler. They require most careful identifi- 

 cation. 



