BIRD-LIFE OF THE SPANISH SPRING-TIME, 257 



Cuckoo's eggs in a nest of that bird, along with three eggs 

 (one broken) of the owner.* 



The Spotted Cuckoo, moreover, lays eggs so exactly 

 resembling those of the selected foster-mother (the Magpie) 

 as to be hardly distinguishal)le. On close examination, it 

 is true, the}' do differ in their more ellipitic form and 

 granular surface : but, unless previously aware and 

 specially on the look-out, no one, probably, would suspect 

 they were not Magpie's eggs — apparently not even that 

 'cute bird itself does so. Even so experienced an ornithol- 

 ogist as Canon Tristram failed to discriminate the differ- 

 ence — this was in Algeria — till the zygo-dactylic foot of 

 the embryos betrayed the secret {Ibis, 1859). 



The Spotted Cuckoo deposits two, three, and even four 

 eggs in the same Magpie's nest — sometimes leaving the 

 original owner's eggs undisturbed, in other cases removing 

 all or part of them : we have noticed spilt yolk and the 

 shells of broken eggs at the entrance to the nest and on 

 the branches below. Hatched thus, in the domed and 

 enclosed nests of the Magpie, it seems difficult for the 

 young Spotted Cuckoos to eject their pseudo-brothers and 

 sisters ; but we cannot speak definitely as to this detail in 

 the early life-history of these curious usurpers of hearth 

 and home. 



The only egg of the Common Cuckoo we have ever found 

 in Spain was in a nest of the Stonechat. This was on 

 April 23rd, and there were four eggs of the Stonechat. 

 The Cuckoo is common in Si)ain on passage, arriving 

 early in April ; a few remain to breed, and we have heard 

 their note up to the end of Ma^^ but the majority pass 

 on northwards at once. 



The Azure-winged Magpie, above referred lo, is very 

 local in the south. It nests not far from Jerez, and in 

 some numbers near Coria del Eio, but is much more 

 abundant in the wooded vegas of Cordova, and still more 

 so in Estremadura and Castile, actualh* swarming near 

 Talavera de la Keyna, at Aranjuez, etc. Their nests, 



* In Egypt the Grey-backed Crow {Corvus comix) is almost ex- 

 clusively the Cuckoo's dupe ; in Algeria, Pica mauriianica. 



S 



