56 THE BIRDS OF THE BRITISH ISLES. 



arrive, the old nests of House-Martins are annexed, and occa- 

 sionally the Sparrow evicts a bird in occupation ; the Sand- 

 Martin also suffers. I have seen in a Surrey sandpit almost 

 every burrow stuffed with the straw and building material 

 of the Sparrows, the nests, on account of the small size of 

 the borings, being close to the entrance. Bulky nests of the 

 Rook are used to support those of the Sparrow, and I have 

 found eggs in an old nest of the Magpie. Five to six eggs, 

 profusely dusted, speckled or blotched with black, brown or 

 ash-grey on a blue-tinted or creamy white ground, are usual 

 types of the very variable eggs — variable in size and shape as 

 well as markings (Plate 34). The hen is said to do all the 

 incubating. 



The plumage of the male House-Sparrow contrasted with 

 that of the Tree-Sparrow is shown on the plate. The bill in 

 summer is blue-black, the legs and irides brown. When clean, 

 the cock Sparrow is an exceedingly handsome bird. In winter 

 the plumage is dulled by pale edgings, and the bill is yellowish 

 brown. The female has no black on head nor throat, nor a 

 grey crown ; her upper parts are streaked with brown. The 

 young are deeper brown, and the white is replaced by buff ; the 

 beak is dull yellow. Length, 6*25 ins. Wing, 2*9 ins. Tarsus, 

 7 in. 



Tree-Sparrow. Passer montanus (Linn.), 



The Tree-Sparrow (Plate 23), a local resident, occurs in 

 most parts of Britain. During the last half-century it has 

 extended its range in Scotland, and is a recent but well-estab- 

 lished colonist in Ireland. Abroad it is spread over most of 

 Europe and Siberia, but allied forms occur in other parts of 

 Asia. Large numbers of migrants reach our north-east coasts 

 in autumn and return in spring ; as a migrant it has occurred 



