72 THE MIGRATIONS OF BIRDS 



that, though these birds were kept below decks, 

 where they had no opportunity to orient themselves, 

 on release they started flight to the east, in the 

 proper direction to carry them toward their home. 

 If we are willing to attribute a sense of direction 

 to some mammals, including man in certain in- 

 stances, I see no reason why we should deny its de- 

 velopment in a high degree in migratory birds. Most 

 of us are familiar with incidents of homing in domes- 

 tic cats and dogs, and may apply the same principle 

 to birds. Certainly an instinct for direction should 

 excite no more astonishment than the instinct for 

 nest-building or the care and rearing of young, 

 found among all birds, or the ability to swim and dive 

 inherent in young grebes, ducks, and sandpipers, 

 when they have burst the shell and are strong 

 enough to move. A young great blue heron that I 

 reared from a tiny chick grew up in a laboratory and 

 its vicinity wholly removed from the influence of 

 others of its species. The fact that, when nearly 

 grown, it evinced an instinctive interest in fish, and 

 for hours at a time remained motionless watching 

 the movements of chubs swimming below a bridge, 

 seems more remarkable to me than the fact that 

 it ultimately left me and wandered as do other 

 herons in autumn. The entire problem of orienta- 

 tion is one that may be cleared eventually by experi- 

 ment, but up to date has no lucid explanation. 



