BIRDS OF THE HOMESTEAD 39 



for he is by no means a homestead-loving bird — the 

 Tree-sparrow appears at times. He may be distin- 

 guished at once from the common form bv his 

 smaller size and by his chestnut head and black- 

 and-white cheek and throat, alike in both sexes. He 

 has nothing of the confident manner which marks 

 the House-sparrow. Although an active, lively 

 bird, he is rarely seen apart from the dense plumes 

 of the topmost fir-branches, and, wherever he may 

 be, he seems to shrink instinctively from observation. 



In England the Tree-sparrow usually nests in the 

 hole of some remote tree, but, curiously enough, in 

 France it appears to have adopted the House-spar- 

 row's habit of frequenting human domiciles and 

 building beneath their eaves. Mr. W. P. Pvcraft 

 recently put forward a theory that at one time all 

 birds nested in trees, supporting this view by the 

 statement that the oldest known fossil-bird — the 

 Archoeopteryx— was a tree-builder, and suggesting 

 that the first cause of birds nesting elsewhere was 

 overcrowding. 



Even if not altogether borne out by the facts 

 this is an interesting speculation, and there is 

 certainlv reason to believe that nest-building is in a 

 state of evolution. The case of the Sparrows seems 

 to bear upon this point. It may fairly be inferred 

 that at one time, when human habitations were few, 

 the House-sparrow constantly built in trees, a habit 

 by no means abandoned to-day; that by degrees 

 houses and other buildings were seen to provide 

 more suitable sites, and that, as the ages went b}^ 

 these were more and more resorted to, until at 

 length they became, as we find them to-day, the 



