S08 BRITAIN'S BIRDS AND THEIR NESTS. 



the most generalised subdivision, retaining, as it were, the 

 ancestral type of plumage. 



The Thrush is found throughout the year in all parts 

 of the British Isles except Shetland. In the Hebrides 

 the birds are noticeably small and dark, a variation 

 probably connected with local conditions and paralleled 

 among the moths and butterflies of the same region. In 

 winter a considerable amount of southward migration 

 takes place, from the more northern parts of our area 

 €specially ; and at the same time our eastern seaboard 

 receives numbers of Song-Thrushes from northern Europe. 

 These may often be seen arriving from a north-easterly 

 direction at the same time as flocks of other species not 

 resident with us in summer. 



With the return of spring the birds settle down again 

 in their usual haunts. The nest is placed in a bush or 

 low tree, and is always recognisable. It is a rather deep 

 cup, and is composed chiefly of grass. The characteristic 

 lining is a layer of hardened mud or dung, finished off 

 with a layer of decayed wood. This lining is watertight, 

 and effectually protects the eggs when the sitting bird 

 itself covers the open top. It is said that the lining 

 is sometimes dispensed with in very dry seasons. The 

 familiar eggs are blue, usually with black spots. There 

 are from four to six in a clutch ; but the larger number 

 is uncommon, at any rate in the northern parts of our 

 islands. Just vmder a fortnight is required for incuba- 

 tion, in which the cock takes a small shai'e. Two or 

 more broods are usually produced in a season. 



The song of the Thrush is well known ; loud and 

 clear, it is to be heard from some high bough in every 

 copse or plantation in spring and early summer, and even 

 in mild winter weather. An oft-repeated series of clear, 

 flute-like notes is a beautifol and characteristic feature. 



