Insect-Eaters and Seed-Eaters, 5 



a seed-eating bird. But how does the cuckoo find out 

 that these are all actually insect-eating birds ? For 

 all differ extremely from each other, both in form and 

 colour, and also in their song, and their call-note. 

 Further, how comes it that the cuckoo can trust its 

 egg and its tender young to nests which are so 

 different with respect to structure, dryness, and 

 moisture ? The nest of the wren is so dry and close, 

 that one would fancy the big young cuckoo would be 

 suffocated in it, yet it thrives there ; it thrives, too, 

 in the nest of the yellow wagtail, which builds upon 

 damp commons in a nest of rushes." 



Eckermann was wrong about the cuckoo invariably 

 choosing the nests of insect-eating birds for its eggs — 

 it sometimes has recourse to nests of seed-eaters ; but 

 the young cuckoos adapt themselves, and flourish just 

 as well. 



But in truth, the very word "insect-eating," as 

 implying a hard and fast distinction from which there 

 is no variation worth noting, is egregiously mislead- 

 ing. Not a few birds which pass amongst the crowd 

 as seed-eaters, such, say, as the Greenfinch, notori- 

 ously, in the time of feeding the young, resort largely 

 to insects and caterpillars ; and I am even inclined to 

 think from facts which have come before me, and 

 which I have myself obserx'ed, that all birds more or 

 less in the time of feeding the young will largely and 

 most astonishingly vary and extend the list of edibles. 

 Canaries, more especially at that time, will devour 

 plant-lice and sometimes even try ants-eggs, which I 

 would not have credited had I not seen it ; for, having 

 once had a nightingale and what is wrongly called a 

 " grass-finch," I first got proof of this by chance, 



