BLACK REDSTART. 139 



Sparrow, the only ones with which they can be con- 

 fused in our islands. The situation of the nest is also 

 an unfailing guide to their correct identification. 



The Black Redstart {Riiticilla tithys) has been said 

 to breed in the British Islands, but there is, as yet, no 

 positive evidence in support of the fact. This species 

 is a fairly numerous winter visitor to our area, and it is 

 not improbable that a few odd pairs may remain over 

 the summer and breed with us. The eggs are usually 

 laid in May. The nest is generally made in an out- 

 building, in holes in walls, and in rock crevices. It is 

 rather a bulky structure, loosely put together externally, 

 but the cup containing the eggs is neat and remarkably 

 well finished. The outer materials are composed of 

 roots, dry grass, moss, straws, and dead stalks of plants ; 

 the cup lined with finer grass, moss, hair, and feathers. 

 The eggs are from four to seven in number, five being 

 an average clutch. They are normally pure white, but 

 occasionally a brownish or bluish tinge is perceptible. 

 Very exceptionally they are minutely and indistinctly 

 speckled with brown on the larger end — a reversion pro- 

 bably to some ancestral colouration. Average measure- 

 ment, 75 inch in length, by "58 inch in breadth. 

 Incubation is performed by both sexes, but mostly by 

 the female, and lasts about fourteen days. Two broods 

 are generally reared in the year. 



