238 FIELD-STUDIES OF RARER BIRDS 



more, though on a sea-cliff this contingency 

 depends largely on the position of the next eyrie 

 (belonging to other two pairs) on either side of it. 

 On a mountain precipice, of course, things are 

 different ; the same face is seldom, I should say, 

 and never in my own experience, of sufficient 

 length to harbour more than one pair of Falcons, 

 though, naturally, in a long rocky valley the 

 occasion may well arise. 



Although individual pairs are prone to use the 

 same site annually, even in the face of persistent 

 robbery, they seldom indeed lay a second " set ' 

 of eggs in that eyrie from which, earlier in the 

 season, the first clutch has been removed. They 

 then almost without exception select a fresh 

 nursery. Although some Falcons patiently submit 

 to their eggs being taken one by one as they are 

 laid, others resent such an outrage after one or 

 two, say, have been snatched in this manner, by 

 shifting to new quarters and finishing the clutch 

 there. 



The Peregrine lays from two to four eggs, 

 usually three or four. The latter is commonly found 

 in the south of England, as well as in the west and 

 from there to Cambria and the Green Isle. 

 Further north, however, a ' three ' is perhaps 

 most general, and in any district a mountain 

 Peregrine, as opposed to a sea-cliff bird, is liable 

 to produce a triplet instead of a quartet. Some 

 ornithologists deny that genuine ' twos " exist, 



