io8 ANIMALS OF NO IMPORTANCE. 



too weak to perform the long journey over the hills ; such 

 birds must, therefore, grill in the plains, while their more 

 fortunate companions are disporting themselves in northern 

 latitudes. There are some who maintain that many quail 

 remain in India during the summer from choice. For in- 

 stance, if they happen to come upon a place where food is 

 particularly abundant, they refuse to leave it when the time 

 for migration comes. This I do not believe. The migra- 

 tory instinct must be so deeply ingrained in the birds that 

 nothing short of necessity would prevent their obedience to 

 its promptings. 



Much has been said of the wonderful way in which the 

 quails migrate each year on almost the corresponding day. 

 As regularly as clock-work they appear in Kumaun in early 

 October on their way south, and again in April on their 

 northward journey. On reflection, however, their regularity 

 of appearance is not surprising. There must be some stim- 

 ulus which sets the migratory instinct in motion, which sud- 

 denly impels the bird to go on its travels. What this stim- 

 ulus is we cannot say for certain. Temperature probably 

 has something to do with it. 



Migration takes place during the night. Throughout the 

 day the birds rest in a field of ripe crops, which provides 

 them with food, shade, and cover. The long journey 

 which the quail takes must occupy several days or rather 

 nights, and if he set out at a time when no food was obtain- 

 able en route, at a time when the fields were all bare, he 

 would almost certainly perish before arriving at his destina- 

 tion. Thus, natural selection tends to fix the period of 

 migration within narrow limits. But, it may be objected, 

 this does not explain how it is that the quail always knows 

 when the crops are ripe, and makes the journey at this 

 period. I do not think that the quail knows that a crop is 

 ripe when he is thousands of miles away. Blind instinct 

 impels him to set out on his travels. After he has flown a 

 long distance he looks out for a halting place and selects 

 the first field of ripe crops that meets his eye. Natural 



