174 BIRD BEHAVIOUR 



of interest, because the Tree-Sparrow is in some 

 respects the most advanced species of the true 

 Sparrows, having in both sexes a coloration which 

 is masculine only in its nearest allies, and the 

 widest distribution, for the House-Sparrow, though 

 actually found in more countries, has in many cases 

 been transported deliberately by man, whereas its 

 rival colonizes on its own account. 



Nesting with a covering of some sort, found 

 existing or constructed, overhead, is a habit of 

 which birds which possess it are very tenacious, 

 and however intelligent they may be in other ways, 

 such birds seldom venture to nest in the open ; 

 of this the Sparrow, Starling, and Sheldrake are 

 conspicuous examples. Nevertheless among birds 

 which make nests as opposed to burrowers, dome- 

 builders are the exception, most constructed nests 

 being open, either mere platforms or piles, such as 

 those of the Woodpigeon and the Moorhen, or 

 advancing to the state of a more or less deep cup, 

 such as is built by most passerine birds. 



Such nests with elevated sides or domed roofs 

 may be built by a process of felting, as when made 

 with moss and similar substances, or actually 

 woven with a skill which is at times most admirable. 

 Unfortunately we are not well off in the north 

 for very skilful nest-builders, and the only woven 

 nest of a British-breeding bird is that of the Golden 

 Oriole, a species unfortunately too much persecuted 

 to have other than the rarest chances of exhibiting 

 its skill ; the nest is a woven hammock, suspended 



