v THE PHILOSOPHY OF BIRDS' NESTS 107 



and it seems highly probable that the older birds would begin 

 building first, and that those born the preceding summer would 

 follow their example, learning from them how the foundations 

 of the nest are laid and the material put together. 1 



Again, we have no right to assume that young birds gene- 

 rally pair together. It seems probable that in each pair there 

 is most frequently only one bird born the preceding summer, 

 who would be guided, to some extent, by its partner. 



My friend, Dr. Eichard Spruce, the well-known traveller 

 and botanist, thinks this is the case, and has kindly allowed 

 me to publish the following observations, which he sent me 

 after reading my book. 



How young Birds may learn to build Nests 

 " Among the Indians of Peru and Ecuador, many of whose 

 customs are relics of the semi-civilisation that prevailed before 

 the Spanish conquest, it is usual for the young men to marry 

 old women, and the young women old men. A young man, 

 they say, accustomed to be tended by his mother, would fare 

 ill if he had only an ignorant young girl to take care of him ; 

 and the girl herself would be better off with a man of mature 

 years, capable of supplying the place of a father to her. 



" Something like this custom prevails among many animals. 

 A stout old buck can generally fight his way to the doe of his 

 choice,, and indeed of as many does as he can manage ; but a 

 young buck ' of his first horns ' must either content himself 

 with celibacy, or with some dame well-stricken in years. 



" Compare the nearly parallel case of the domestic cock 

 and of many other birds. Then consider the consequences 

 amongst birds that pair, if an old cock sorts with a young 

 hen and an old hen with a young cock, as I think is certainly 

 the case with blackbirds and others that are known to fight 

 for the youngest and handsomest females. One of each pair 



1 It has been very pertinently remarked by a friend that, if young birds 

 did observe the nest they were reared in, they would consider it to be a 

 natural production, like the leaves and branches and matted twigs that sur- 

 rounded it, and could not possibly conclude that their parents had constructed 

 the one and not the other. This may be a valid objection, and if so, we shall 

 have to depend on the mode of instruction described in the succeeding para- 

 graphs, but the question can only be finally decided by a careful set of 

 experiments. 



