BROOD-CARE IN BIRDS 153 



perhaps the primitive colour, is white as in the case of 

 reptiles. In a very large number of birds belonging to different 

 groups and with different habits the white colour is retained. 

 Perhaps the most common case is that of birds which lay in holes 

 or in covered nests, and it has been suggested that it is an advantage 

 in such circumstances, for white is more visible in dim light, and 

 therefore possibly a bird entering its dark nesting-place might see 

 its eggs more easily if they were white. I cannot believe, however, 

 that birds are so stupid as to run any great danger of missing their 

 own eggs. The fancy of museum naturalists has even led them to 

 suppose that a bird like the English puffin, which has a coloured 

 egg overlain by a white chalky encrustation, has only recently come 

 to occupy burrows in the nesting season, and so has contrived to 

 cover up the colour of its eggs. Cormorants, however,, nest on the 

 open ground and similarly have eggs the pale blue or green colour 

 of which is concealed by a coating of chalky white, and Guira 

 cuckoos, which build open nests, have pale blue eggs partly covered 

 with a network of chalk. Another explanation perhaps errs in 

 attributing too much intelligent reasoning to the birds. This 

 is that many birds whose eggs happen to be white take them 

 to holes to hide them. 



We are on safer ground if we simply remember that if the eggs 

 of birds were originally white, there can at least have been no 

 disadvantage in that colour being retained by those which are laid 

 in holes and other dark places. The ostrich buries its white eggs in 

 the sand. Bar bets, bee-eaters, hornbills, jacamars, kingfishers, 

 motmots, owls, parrots, a few pigeons, rollers, todies, toucans, 

 trogons and woodpeckers all lay their white eggs in holes in the 

 ground or in the hollow branches of trees. But curassows, frigate- 

 birds, fiogmouths, most herons and bitterns, many of the smaller 

 birds- of-prey, colies, pelicans, most pigeons and storks make open 

 platforms or nests visible from above and yet still lay white eggs. 

 The apteryx has white eggs laid on the ground, roughly concealed 

 under foliage. The larger birds-of-prey have white eggs or eggs 

 blotched with red and lay them in the open. The eggs of ducks, 

 geese, swans and flamingoes are glossy white, or at the most have a 

 pale tint of yellow or blue ; many of the game-birds have eggs that 

 are nearly white, those of grebes are white, although later on they 

 become stained from the wet moss and reeds of the nest, pelicans 

 have white eggs, penguins have eggs that are white or nearly white, 

 screamers have white eggs, trumpeters have white eggs, and all 



