THE ^yTLD BIRD AT ARM'S LENGTH. 



203 



Let ns sec how these principles are a})})lied to the i)i'ol»h'iii of ap- 

 proaching wild birds in the way described. The parental instincts 

 begin to control the life of the adult with the ])eriodic revival of the 

 reproductive functions, and may vary greatly in their scope and inten- 

 sity. As a rule this instinct, reinforced by habit, gradually increases 

 until the young are reared. It is, therefore, safest to change the nesting 

 surroundings when the ])arental instincts are approaching their cidmi- 

 nation. 



The general feeling of fear is gradually or quickly suppressed 



Fig. 4. Kingbirds, bruising a Dragon-fly between their Bills, and preparing to serve 



IT TO THE Young. The Female, who was brooding when the Prey was 



cai'ght, stands at the Front. 



according to the value of the different factors in the equation, by the 

 parental instinct, which impels a bird at all hazards to go to its young 

 wherever placed. 



After a bird once visits the nest in its new position it returns again 

 and again, and in proportion as its visits to the old nesting ]ilace dinun- 

 ish and finally cease, its a])proaches to the new position become more 

 frequent, until a new habit has been formed, or, if yon will, until the 

 old habit is reinstated. 



When the birds ai)proach the nest any strange object, like the 

 stakes which support the bough or the tent which is |)itched beside it, 



