Woodland Birds 



decidedly brown ; that of the Coal Tit is greenish 

 olive. The nests of all four species are rather 

 loosely-made structures of moss, wool and hair, 

 lined with feathers, and placed in holes, either in 

 a tree or a wall. The Great and Blue Tits are, 

 however, by no means particular, showing quite a 

 penchant for lamp-posts, and they have, on occa- 

 sion, patronised letter-boxes, pumps, gateposts, 

 shutes, and other out of the way places. 



For some reason or other the eggs of almost all 

 birds that nest in holes are pure white or, at most, 

 white spotted with red, the Tits' being among the 

 latter. It is easy to explain the coloration of some 

 species of eggs, the Plover's for example, on the 

 ground that it is protective. For eggs in holes 

 protective colouring is, of course, unnecessary, and 

 that, I suppose, accounts for the complete absence 

 of pigment. When there is no longer any use for 

 a thing Nature slowly but surely takes it away. 

 Still, protection is not the only consideration 

 regulating the colour and marking of eggs. 

 Those of the Thrush, for instance, are most con- 

 spicuous as they lie in the nest, and there could 

 hardly be a greater contrast than that formed by 

 the white eggs of the Woodpigeon and the dark 

 platform of twigs on which they are laid. 

 Obviously, the theory of protection does not hold 

 good here, but we have not space for mere con- 

 jecture. 



What a change comes over the woodlands with 



53 



