340 TROPICAL WILD LIFE IN BRITISH GUIANA 



and these habits, in turn, will finally become practically an 

 instinct to them. 



But to return to our martins ; when I had destroyed the 

 second nest a few days later, they did not attempt a third, 

 but still continued to roost there each night. Penard tells us 

 of taking four sets of eggs from the nest of a pair of these 

 birds and still they would not leave. In this instance the 

 habit of living in one place was supreme and clearly domin- 

 ated the instinctive idea of seeking a safer home. Undoubt- 

 edly the idea would become uppermost if the persecutions 

 kept up. 



As has been said, individual habit and instinct are so 

 closely allied that it is hard to distinguish between them, but, 

 nevertheless, there are certain points where the line may be 

 drawn, of instinct as subordinate to new habit. Thus the 

 young martins, in spite of all their homing instincts, could 

 not find their home until they had determined, through repe- 

 tition, in which of the four holes it was located. Such knowl- 

 edge was acquired only after many trials and trips, whereby 

 a habit of arriving at the right point was created. The re- 

 sults of the experiment with colored eggs may be put down 

 to either instinct or habit, yet, as the birds must have realized 

 that the eggs were different, it may have been habit more 

 than instinct that caused them to continue the incubation. 

 There can be no doubt, however, that from habit only, they 

 roosted and started a new nest in the same place, after the 

 old had been destroyed. This habit would have proved 

 costly, if the nest had been destroyed by an enemy which, 

 after new eggs were laid, would have returned to repeat its 

 performance. 



Evidence also points out that a certain few of their daily 

 actions in the round of life are due, not so much to inborn 

 instinct as many believe, but to habits acquired from a youth- 

 ful training by their parents, from experience, and from a 

 wide sense of imitating their elders. For instance, the young 

 bird has to be taught how to catch insects. He knows that 



