324 WILD LIFE IN A SOUTHERN COUNTY. 



progeny with its own. offspring. Irrespective of size, 

 the plumage is so different. And there is another reason 

 why they must know the two apart : the cuckoo as 

 he grows larger begins to resemble the hawk, of which 

 all birds are well known to feel the greatest terror. 

 They will pursue a cuckoo exactly as they will a 

 hawk. 



I will not say that that is because they mistake it 

 for a hawk, for the longer I observe the more I am 

 convinced that birds and animals often act from 

 causes quite distinct from those which at first sight 

 appear sufficient to account for their motions. But 

 about the fact of the lesser birds chasing the cuckoo 

 there is no doubt. Are they endeavouring to drive her 

 away that she may not lay her egg in either of their 

 nests ? In any case it is clear that birds do recognize 

 the cuckoo as something distinct from themselves, 

 and therefore I will never believe that the foster- 

 parent for a moment supposes the young cuckoo to 

 be its own offspring. 



To our eyes one young robin (meaning out of the 

 nest on the hedge) is almost identical with another 

 young robin ; to our ears the querulous cry of one for 

 food is confusingly like that of another : yet the vari- 

 ous parent birds easily distinguish, recognize, and feed 

 their own young. Then to suppose that, with such 

 powers of observation with the keenness of vision 

 that can detect an insect or a worm moving in the 

 grass from a branch twenty feet or more above it, and 

 detect it while to all appearance engaged in watching 



