Books prefer Ehn Trees. 235 



useful to alight on when bringing food for the 

 joung. 



It may be that the difficulty of finding trees which 

 afford all these necessary conditions is one reason 

 why rooks who settle at a distance from their city seem 

 long before they can please themselves. The in- 

 genuity exercised in the selection of the bough and 

 in the placing of the twigs is certainly very remark- 

 able. When the wind blows furiously you may see 

 the nest moving gently, riding on the swajdng boughs, 

 while one of the birds perches on a branch close by, 

 and goes np and clown like a boat on the waves. 

 Except b}' the concussion of branches beating hard 

 against the nest, it is rarely broken ; up to a certain 

 point it would seem as if the older nests are the 

 firmest, perhaps because of their weiglit. Sometimes 

 one which has been blown down in the winter — when 

 the absence of protecting leaves gives the wind more 

 power on them — retains its general form even after 

 striking against branches in its descent and after 

 collision with the earth. 



Elms are their favorite trees for building in. Oak 

 and ash are also used, but where there are sufficient 

 elms they seem generally preferred. The&e trees, as 

 a rule, grow higher than any others ordinarily found 

 in the fields, and are more frequently seen in groups, 

 rows, or avenues, thus giving the rook facilities for 

 placing a number of nests in close neighborhood. 

 The height of the elm affords greater safety, and 

 the branches are perhaps better suited for their 

 purpose. 



After building in an elm for many years — per- 

 haps ever since the owner can remember — rooks will 



