Merciless Ejection. 13 



had just been laid there by the cuckoo. Moreover, 

 Herr Grunack {Joiinial fiir Orn., 1873, P- 454) has 

 since found one of the most abnormally-coloured 

 specimens, quite unlike the ordinary egg of the cuckoo, 

 to contain an embryo so fully formed as to show the 

 characteristic zygodactylic feet of the bird, thus 

 proving unquestionably its parentage." 



The fadl that the young cuckoo mercilessly ejeefls 

 from the nest and makes an end of his foster-brothers 

 is now just as well established as that the parent 

 drops the eggs into other birds' nests. Soon after 

 being hatched, the young cuckoo exhibits great rest- 

 lessness, irritabihty, and energy. Whatever is in the 

 nest it endeavours to get under. It keeps on beating 

 its stumps of wings, and as it gets older will spar with 

 its wings and peck at the finger, if placed near it. 

 The other nestlings are usually disposed of by it 

 during the second or third day, and any eggs share 

 the same fate as the young birds. It will permit 

 nothing in the nest beside it — whatever is dropped in, 

 it will lift up and throw over the edge. Difficulties 

 have been raised about the possibility of the young 

 cuckoo throwing the other nestlings out of domed 

 nests ; but these are much reduced, if not met, by the 

 fact that in open nests, set in certain positions, the 

 area on the edge of the nests which the young cuckoo 

 could make available is but one-fifth of the whole 

 circumference, and that it has a special instinct for 

 working always toward the open portion ; besides all 

 which the birds in the domed nests it favours would 

 generally be very small birds. Later observations 

 prove that in addition to great strength of shoulder 

 and wing stump, the young cuckoo is aided by a 



