82 BIRDS' NESTS 



claim to be considered as nest-builders of a somewhat 

 higher class {conf. pp. 139, 152); whilst even amongst 

 the birds in the remaining sub-order, the Anseres, the 

 nests are by no means of a uniform degree of crude- 

 ness, some being much more elaborate than others. 

 We cannot exactly class the nests of the Swans 

 (Cygnin^), and at least some of those of the Geese 

 (Anserinae), as crude, and must reserve them for 

 inclusion in another chapter. Even amongst the 

 more crude nest-building Ducks there is considerable 

 diversity, not only in the situation of the nest, but in 

 the elaborateness or otherwise of the structure pro- 

 vided. Notwithstanding their undoubted crudeness, 

 the nests of most Ducks are, when completed, very 

 beautiful structures. This beauty is almost entirely 

 derived from the dense warm lining of down plucked 

 from the female's body, and added as the eggs are 

 laid or as incubation progresses. Crude as the nests 

 of the Ducks are, we have several very distinct types. 

 Broadly speaking, the nests are either concealed in 

 holes or placed among vegetation of some kind. The 

 normal hole-building Ducks include such species as 

 the Golden-eyes, the Buffel-headed Ducks, the Mer- 

 gansers, and the Smew. None of these hole-breeders 

 can be said to make any nest. The hole in a tree is 

 selected ready-made, and the eggs are deposited upon 

 the decayed or powdered wood at the bottom, but a 

 warm lining of down is eventually added. Then we 

 have the various species of burrow Ducks that incubate 



