NESTS AND NEST-BUILDING IN BIRDS 341 



the guarding instinct which is strongest in the male. This 

 guarding, moreover, begins at the time the nest site is chosen, 

 before the building operations have fairly begun, and reaches 

 a climax when the young are ready for flight. 



If the building female is disturbed at any point in her ^vork, 

 she usually comes to attention, putting up her head, as if listen- 

 ing; then, it may be, she gives the alarm call, when the male 

 who is close at hand, immediately responds, and appears on 

 the scene ready for any emergency; for a moment the mask 

 of secrecy is thrown off. The observer soon comes to be dis- 

 regarded, if he remain perfectly quiet, whatever his position, 

 but let him drop his pencil and stoop to pick it up, or make 

 any unusual movement, he is detected at once; the worker 

 sounds an alarm, makes a feint at flying straight at him, but 

 swerves when within a few feet of his head , and goes off for more 

 straw or mud. Nothing seemed to escape the vigilance of this 

 guarding male, and whenever another robin or any strange 

 bird trespassed on his preserves, it was immediately assailed 

 and driven oft' with such outbursts of fiery pugnacity that it 

 was fortunate to escape. 



The Selection of Nest Material. — During the period of obser- 

 vation at this nest it was noticed that the materials were drawn 

 from four dift'erent points, now from one, now from another, 

 stubble, including dead grass and weeds from a field a few 

 hundred feet away, the grass being occasionally pulled up by 

 the roots with a considerable amount of adherent earth, mud 

 from two points along a neighboring creek, and rootlets, dead 

 weed stems and the like from a ploughed garden close at hand. 

 While the female worked the cock stood quietly on guard, either 

 in the nest tree or in another close at hand. When the work 

 of a given visit was over, she would draw up to attention, pause, 

 and flv low, closely accompanied by the male, to one of the 

 points in question. Both on her departure and return the female 

 usuall}^ took the lead, the male flying after her or abreast, and 

 often within a few feet; but less commonly while keeping to 

 her direction he would be farther to one side or in the rear. 

 Alighted on the ground the pair would hop along together, 

 the female making sundry dabs with her bill until a load was 

 gathered. The general impression conve3^ed is that there is 

 no hesitation as to where to go or what to get, any more than 



