HOUSE SPARROW. 31 



year, and if destroyed, new ones will be made on the 

 same sites, for the House Sparrow is greatly attached 

 to its breeding-place. Both male and female assist in 

 building the nest, and the thieving propensities of build- 

 ing birds often lead to combats. Brood after brood is 

 reared in the same nest. 



Range of egg colouration and measurement : 

 The eggs of the House Sparrow vary from four to six 

 or even seven in number, five being the average clutch. 

 They vary from bluish-white to pale grayish-brown in 

 ground colour, more or less thickly mottled, blotched, 

 and spotted with various shades of brown and gray. 

 The eggs of this species present considerable variation, 

 both as regards size, shape, and colour. Certain varieties 

 are so thickly mottled and spotted that the ground 

 colour is almost, if not entirely, concealed ; others have 

 the surface-spots small, ill-defined, and distributed over 

 the entire surface of the shell ; others have the spots fewer 

 in number, but large and boldly defined ; whilst others, 

 yet again, have a zone of colour round the large or small 

 end. In some the markings are chocolate-brown ; in 

 others, ash-brown or reddish-brown. Average measure- 

 ment, "9 inch in length, by "6 inch in breadth. Incuba- 

 tion, performed by both sexes, lasts fourteen days. Very 

 often the eggs are sat upon as soon as laid. It might 

 also be remarked that in many instances one odd &<g^ in 

 a clutch is differently marked than the rest. 



Diagnostic characters : It is impossible to give 

 any character by which the eggs of the House Sparrow 

 may always be distinguished from those of allied species. 

 Eggs of the Tree Sparrow are often indistinguishable ; 

 as are also eggs of the Pied Wagtail and the IMeadow 

 Pipit. As a general rule, the situation of the nest is a 

 safe and unfailing guide to the identification of the eggs. 



