390 LIFE-HISTORIES OK 



Nest building has been observed as early 



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March 15, but then only in sheltered localities on 

 the south slopes of hills. Here the nests are built 

 most generally in the branches of coniferous trees. 

 Usually bu't a single brood is reared in a season ; 

 but we have met with a second brood when the 

 weather has been unusually propitious. In such 

 cases the first batch of young appeared about the 

 middle of April, and the other early in July. 

 Nidification ordinarily commences from the 2Oth 

 to the 28th of April. A nest is the product oi the 

 joint labor of the sexes for a period of six days, 

 working with considerable diligence. The day 

 following the completion of the nest, the female 

 begins to deposit her eggs to the number of six, 

 at the rate of a single ovum per day. Incubation 

 follows on the clay succeeding the last deposit, and 

 is the sole business of the female for about sixteen 

 days. The male-bird keeps very close watch over 

 his partner in the nest, when not employed in 

 providing nourishment for her and himself. When 

 the nest is assailed, both parents seek to drive 

 away the intruder by loud clamors and threatening 

 gestures; flying close to his head with open jaws 

 and fury-darting eyes. Where the offender has 

 been one in feathered dress, we have known 

 several pairs to come to the assistance of their 

 besieged friends, when the most deafening cries 

 and wildest excitement would prevail. Such is the 

 bravery with which some parents defend their 

 nests and young, that in encounters with human 



