PEREGRINE FALCONS 241 



puzzle to me is where all these unmated birds come 

 from, how does the survivor at any given eyrie 

 know where to look for them? For the occur- 

 rence is too common to warrant any element of 

 chance. Another interesting point is the usual 

 quickness with which a vacant and obviously recog- 

 nized site is appropriated. Where would the 

 appropriators have bred had the site not been 

 free, and had there been no more " availables " in 

 the neighbourhood ? ' Gone elsewhere," you 

 would say. Just think a moment, and you will 

 remember that, once a pair of birds (of any sort) 

 have fixed their fancy on a neighbourhood, it takes 

 more than a " filled vacancy " to drive them away. 

 Here we have, I believe, the reason of sometimes 

 finding two pairs of such a segregated species as the 

 Peregrine breeding in for them really close 

 quarters. I have already mentioned that I have 

 on several occasions known of two tenanted eyries 

 within, roughly, a quarter of a mile. 



Save by the merest chance (as, for instance, 

 when the eggs are laid in a scraping in a thick 

 bed of cotton-grass), the eggs never touch one 

 another in the eyrie, each one lying from half an 

 inch to two inches, or occasionally even more, 

 from its fellow, the entire clutch therefore, 

 according as to whether there are three or four 

 eggs, being arranged in the form of an irregular 

 triangle or rough square, each egg forming a 

 point to connect each imaginary line. On those 



