1909- Nofes. 223 



ZOOLOGY. 



The Use of Domed Nests. 



Mr. Moifat, in his delightfully original article, has pointed out a use 

 for domed nests that I have never seen suggested, namely, as safety- 

 cradles for large broods. The struggles of a brood of Long-tailed Tits 

 within the elastic walls of the nest, which yield like a bag, may be 

 watched. The smallest species have large clutches, and these are laid 

 either in holes or domed nests, or, in the case of the Goldcrest, in a 

 specially constructed cradle, so well described bj' Mr. Mofiat, which is of 

 materials very similar to the nest of the Long-tailed Tit, and in which 

 the young are embedded in a mass of little feathers. 



This brings me to the subject of warmth, which all very small nestlings 

 need so vitally in our climate. The members of the large broods help to 

 keep each other warm, but that is not enough. The}- must either be 

 ensconced in holes, or have covered nests, and on this use of the dome 

 Mr. Moffat has not dwelt. 



That the dome serves for concealment, I think there can be no doubt. 

 White, or nearly white eggs, being conspicuous objects, are, with few 

 exceptions, placed in covered nests, and, where these are not in holes, 

 they must have domes. This is the case with all the species named by 

 Mr. Moffat, except the Magpie, of which I have more to say, and these 

 domed nests are self-concealing from the nature of their position and 

 materials. Thus, a Chiff-chaff accumulates a mass of dead leaves and 

 rubbish, that looks as if it had been lodged among the briars or shrubs 

 accidentally ; the Willow Wren's nest is so buried in ground-herbage as 

 to be most difficult to detect ; the Long-tailed Tit's nest is like a knot on 

 the lichen-covered tree ; while that of the Dipper is like a moss-covered 

 stone, even when it is on an open rock, the buttress of a bridge, or the 

 branch of a tree, it resembles a mossy tussock or a lodgment of rubbish. 

 It is seldom accessible to the spray of a waterfall, though it is a protec- 

 tion against the draught of the river-course. 



Nests of the House-Martin in sea-cliffs are, usually, much higher above 

 the spray than where the open nests of Shags and Kittiwakes are some- 

 times built. The protective colouring of the former makes them 

 difficult to distinguish against the rocky back-ground. Nests of this 

 species are so stuck in the caves or under overhanging rocks, which serve 

 as a roof, that there is seldom room for any dome, but no doubt 

 they serve the purposes of domed nests, and the white eggs could not be 

 better concealed. 



It is otherwise with the Magpie, whose fortification of thorny twigs is, 

 probably, for a defence against crows, which wouldbe met at the entrance 

 by the beak of the hatching Magpie. The conspicuous plumage may 

 also need to be obscured from above, as Mr. Wallace has suggested, but 

 the covering of twigs does not protect from cold nor exclude light. 

 Magpies' eggs are coloured, and do not come under the category of those 

 which need the shade of a dome or burrow. True, the Magpie's nest- 

 covering may prevent " bubbling over " of her brood, which is, usually, 

 larger than that of other Corvidae. 



