COW-PEN BIRD. 497 



When the female returns, and finds in her nest an egg which she imme- 

 diately perceives to be different from her own, she leaves the nest, and 

 perches on a branch near it, returns and retires several times in succes- 

 sion, flies off, calling loudly for her mate, who soon makes his appear- 

 ance, manifesting great anxiety at the distress of his spouse. They visit 

 the nest together, retire from it, and continue chattering for a consider- 

 able time. Nevertheless, the obnoxiovis egg retains its position, the bird 

 continues to deposit its eggs, and incubation takes place as usual. The 

 egg of the Cow Bird is of a regular oval form, pale greyish-blue, sprink- 

 led with umber-brown dots and short streaks, which are more numerous 

 at the larger end. 



Incubation has been continued for nearly a fortnight, and the young 

 Cow Bird bursts the shell. Another remarkable occurrence now takes 

 place. The eggs of the foster-bird are yet unhatched, and soon after 

 disappear. In every case the Cow Bird's egg is the first hatched, and 

 herein also is manifested the wisdom of Nature ; for the parent-birds find- 

 ing a helpless object, for whose subsistence it behoves them to provide, 

 fly off to procure food for it. The other eggs are thus neglected, and 

 the chicks which they contain necessarily perish. Birds have probably 

 the means of knowing an addle egg, for, when any such remain after the 

 hatching of the others, they always remove them from the nest ; and, in 

 the present case, the remaining eggs are soon removed, and may some- 

 times be seen strewn about in the vicinity of the nest. In the case of 

 the Cuckoo matters are differently managed, for the young bird of that 

 species very ungratefully jostles out of the nest all his foster-brothers and 

 sisters, that he may have room enough for himself. If we are fond of 

 admiring the wisdom of Nature, we ought to mingle reason with our ad- 

 miration ; and here we might be tempted to suspect her not so wise as 

 we had imagined, for why should the poor Yellow-throat have been put 

 to the trouble of laying all these eggs, if they are, after all, to produce 

 nothing ? This is a mystery to me ; nevertheless, my beUef in the wis- 

 dom of Nature is not staggered by it. 



As the young Cow-Bird grows up, its foster-parents provide for it 

 with great assiduity, and manifest all the concern and uneasiness at the 

 intrusion of a stranger, that they would do were their own offspring 

 under their charge. When fully fledged, the young bird is of a sooty- 

 brown colour. Long after it has left the nest, it continues to be fed by 

 its affectionate guardians, until it is at length able to provide for itself. 



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