THE ROOK AND JACKDAW 49 



nests in the forks of trees, where a pile of sticks would obviously be of 

 use in providing the structure with a solid foundation. That the 

 change of site was not accompanied by a change in the method 

 and material of construction is easy enough to understand, seeing 

 that there was nothing in the new departure to make this necessary. 

 The practice, therefore, of carrying sticks to the hole has persisted, 

 on the present hypothesis, merely as a harmless survival. It is much 

 more marked, however, in certain individuals of the species than in 

 others. In some cases the sticks are dispensed with, there being 

 nothing but a few twigs, or a little wool, moss, or grass. The 

 absence of the necessity for sticks gives, in fact, free play to individual 

 variations. 



In favour of the view that the jackdaw's partiality for holes is of 

 recent date may be urged the fact that the species still does occasion- 

 ally build nests in trees. Further, if we grant that the normal colour 

 of the eggs of hole-nesters is white, then the fact of the jackdaw's 

 egg being coloured and spotted provides an additional argument. 1 



Another practice which the daw appears to inherit from a former 

 state is that of holding by the middle any long stick it carries. The 

 rook does the same thing. No great inconvenience results when, as 

 in the case of the latter species, the object is merely to place the stick 

 in the fork of a branch. But to effect its entrance held crosswise into 

 a small hole is quite another matter, as the daw soon discovers, or 

 rather as he, in a sense, does not discover, for he will zealously 

 repeat the experiment with different sticks, only to end by dropping 

 them to the ground, where they go to swell the barrow-loads already 

 lying at the foot of the wall. It would be very interesting to find out 

 whether any individual birds succeed in overcoming the difficulty, and 

 whether, having, accidentally perhaps, drawn the stick by its end into 

 the hole, they continue to do so on subsequent occasions. When the 



1 For evidence that the jackdaw builds nests in trees, see the Zoologist, 1843, p. 185; 1845, 

 p. 823 ; 1847, p. 1774 (J. Wolley) ; 1865, p. 9572 ; 1885, p. 264 ; 1901, pp. 70 and 154 ; and the Field, 1875, 

 xlv. 515 (several instances) ; id., 1893, Ixxxi. 470 ; id., 1903, ci. 775 (F. C. Selous and J. G. Cornish), 

 814 ; W. H. Hudson, Birds and Man, p. 71 ; North Staffs Field Club Rep., 1901 ; Norfhants Nat. 

 Hist. Soc. Rep. 1899, p. 174. 



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