BRITAIN^S BIRDS AND THEIR NESTS. 171 



marked in some cases. The plumage varies considerably 

 with age, although not changing with the season. The 

 prevailing hue of immature birds and of adult females is 

 usually a rich, wann, rufous brown. Adult males tend 

 to show slaty-blue colours, especially on the tail. As 

 with Game-birds, old, infertile females may assume male 

 plumage. All the members of the Order we have to deal 

 with belong to the typical group, that of the Falcons (in 

 the widest sense). Vultures and others do not concern us, 

 and to them the above remarks are not all meant to 

 extend. In nesting economy the Peregrine Falcon is also 

 fairly typical of the British Birds-of-Prey. 



As already indicated, the Peregrine nests on cliffs. 

 These cliffs may be coastal ones, or be far inland 

 mountain -walls fronting on the moorland. Other sites 

 are rare in this country ; but old nests of Crows, Herons, 

 and other tree-nesters are sometimes utilised. The species 

 has been recorded as nesting on buildings, and in parts 

 of northern Europe and Asia it has of necessity to lay 

 on the open tundra. The birds, it is almost certain, pair 

 for life, remaining together throughout the year. The 

 rapidity with which another mate is found in case of 

 accident to one of the pair has been frequently remarked 

 upon. A single nesting haunt is often inhabited for many 

 years in succession, but not necessarily by the same pair 

 of birds, as shown by cases like that where one locality 

 'in Connemara known in 1684 to have been inhabited 

 from time immemorial is still (about 1899) inhabited.' 



For a nest the Peregrine Falcon usually chooses a 

 natural crevice or scraped-out hollow on the cliff-ledge, 

 no lining being added. The two to four, but usually 

 three, eggs may be laid in April, but often not until 

 much later. Maritime eyries, we have some ground for 

 believing, receive their eggs considerably later than those 



