1903 Notes on the Nests and Eggs of Birds 205 



embryo offspring, and that so successfully that in spite of 

 much and constant persecution the wood-pigeon increases 

 rather than diminishes in number, whereas the stock-dove 

 (the rabbit-hole breeding race, in Norfolk at any rate) 

 becomes less numerous every year. 



We now come to the most highly specialised eggs in 

 point of colour, those having a tinted ground, with spots, 

 streaks, or blotches of a darker hue superadded. These 

 are all laid in more or less open nests, and are adapted 

 generally to their environment for the purpose of con- 

 cealment. This means of protection is perfected in the 

 Waders, and its absence more or less in the Warblers is 

 compensated for by the selection of a less conspicuous 

 site for, and a more careful construction of, the nest. 

 The general tone of colour in the plumage of the in- 

 cubating parent is also more in harmony with surrounding 

 objects. The nightjar is a very good example of this 

 latter exception. Where the plumage of the sexes differ, 

 and the male alone incubates, display has to give way to 

 caution, and he, as in the case of the dotterel, has to be 

 contented with a more sombre garb than the female. 



We may now perhaps be in a position to answer the 

 question partly, if not quite satisfactorily, as to why the nest 

 of the coot should differ from that made by the great crested 

 grebe. Building in almost juxtaposition, and obtaining their 

 own and their offspring's food-supply from the same waters, 

 yet the composition of that food differs : insects and their 

 larva enter into the dietary of both species, but the adult 

 coot is almost entirely a vegetable feeder, whereas the parent 

 grebes subsist upon fish alone. Their prey is fugitive, and 

 needs pursuit, entailing far longer absence from the nest 

 than is the case with the coot : hence we may argue the 

 need for the miniature hotbed which the nest of this species 

 resembles. Again, why should the coot be able to leave her 

 eggs uncovered whilst she is off feeding, whereas the grebe 

 carefully hides hers up ? The eggs of the former are pro- 

 tectively coloured, whereas those of the grebe are not. To 

 show the sufficiency of the peppery dots of colour upon the 

 eggs of the coot to protect them from foes, let me relate an 

 unsuccessful experiment of my own. In the spring of 1893 



