138 THE RIDDLE OF MIGRATION 



left, 25 per cent are not accounted for, 50 per cent 

 have been returned from the south, while nothing 

 has come in from the north. The country to the 

 south and east of Edmonton is well populated and 

 was excellently patrolled. The districts north and 

 west are less heavily settled and soon give place to 

 wilderness. One can hardly believe that 50 per cent 

 of the controls should have been recovered to the 

 south and only 15 per cent of the experimentals if the 

 latter had also mostly gone south. Had there been a 

 general dispersal in all directions from Edmonton 

 returns from the south and east should greatly have 

 outnumbered those from the north and west for 

 there must have been a dozen watchers in the south 

 to every one in the north. Yet the number of ex- 

 perimental returns was the same in each case (15 

 per cent) again suggesting that the Lesser Slave 

 Lake crows must have represented some, at least, 

 of our lost experimentals. 



While circumstantial evidence thus strongly sug- 

 gests that a majority of our experimental birds 

 travelled northwest, the final verdict must remain 

 open since not even one of the Lesser Slave Lake 

 crows was secured. Although quite improbable, 

 they may actually have been wild birds that win- 

 tered there for reasons unknown. For the sakeof 



