54 ENGLISH BIRD LIFE 



places within Great Britain, is also due to the move- 

 ments of these displaced wanderers. In addition to 

 this, heavy and long-continued snow drives the 

 Robin from its more remote haunts, and the birds 

 then congregate about the homesteads, where food 

 is more easily to be obtained. 



In regard to the conflicts in which Robins engage, 

 it would be interesting to know the exact extent of 

 the evidence upon which the high authority just 

 quoted bases his conclusion that the battles usually 

 take place between the older and younger birds. It 

 has lonof been a well-observed fact that Robins 

 appear to parcel out the countryside into definite 

 tracts, each division being tenanted by a single pair, 

 and that the cock bird is always prepared to resent 

 to the uttermost any encroachment on his territory. 

 This characteristic may be readily tested by placing 

 a caged Robin, or even a stuffed specimen, within 

 the border-line of one of these domains. A single 

 bird at once appears and attacks the intruder with 

 the utmost ferocity, beating with rufHed plumes 

 against the bars, utterly careless of the limed twigs 

 which the bird-catcher may have set for him. When 

 the first bird is taken, no other is forthcoming, at 

 least for a considerable time, when the division 

 may be presumed to have found a new occupant. 

 It is therefore highly probable, as Yarrell states, 

 that a younger generation, seeking a settled loca- 

 tion, are the more frequent encroachers ; but it is 

 none the less true that the cock Robin in possession 

 is often called upon to give battle to a rival, without 

 any distinction of age. 



This habit of attacking an invader of its own 



