220 WOODLANDERS AND FIELD FOLK 



sharing in the spoil. On such occasions it perches 

 on a high tree, and, when a bird is shot, skims down 

 and carries it off before the sportsman can get near 

 it. Another interesting fact in connection with 

 the history of the bird is that it regulates its move- 

 ments entirely by those of the lemmings; and as it 

 follows these little rodents along the mountain 

 ranges to lower latitudes, it is thus often found to 

 breed abundantly in countries where previously 

 it had only been known as a straggler. In this case 

 it is at once apparent that migration is closely 

 connected with food supply, as the bird follows the 

 rodents, keeping them in sight the whole time. The 

 question of food is probably the predisposing cause 

 of all migratory movements; but whether it is 

 " instinct " or reason which teaches our host of 

 summer birds to return to the place of their birth 

 to the self-same eave or bush is a difficult question 

 to determine. It is abundantly proved, however, 

 that memory and observation are the great aids in 

 the case of the best homing pigeons, many of which 

 fly five hundred miles at a stretch. 



Immediately after the enclosure of the commons 

 in North Britain, great numbers of grouse were 

 killed by flying against the wire fences. Now, 

 however, that the birds have become accustomed 

 to these, casualties rarely occur, or only during 

 thick, hazy weather. This also applied to telegraph 



