64 LIFE-HISTORIES OF BIRDS 



TortricidcC) both in the larval and pupal stages, 

 are eagerly devoured. 



The period of nidification commences during 

 the latter part of April, or the beginning of May. 

 For the accommodation of a nest, the hollow of a 

 decayed tree is ordinarily selected. When this is 

 not to be obtained, the birds will not hesitate at 

 much expense of time and labor, to excavate one 

 either in decayed or solid wood. We have never 

 known it to build in trees in close proximity to 

 human habitations, but always in well-woocled 

 regions. That feeling of sociability which charac- 

 terized the species during the inclement weather 

 of winter, is now merged into the all-absorbing 

 one of paternity. 



The nest is a warm, soft, felted mass of hair and 

 fur of small quadrupeds and down of birds; fine, 

 dry grasses and mosses line the cavity, w r hich are 

 placed and contracted into a purse-like opening 

 when the cavity is unnecessarily large. 



The period of incubation has not been definitely 

 determined, but we are inclined to the opinion 

 that it does not exceed 10 days. The young birds 

 are objects of the tenderest solicitude upon the 

 parental part. When the nest is assailed by other 

 than human enemies, the most determined perti- 

 tinacity and bravery are displayed; but in the 

 case of a human foe, the parents remain silent 

 and passive spectators of the violence committed. 

 A single brood is raised in a season, according to 



o o 



our experience; although some ornithologists 

 consider the species double-brooded. 



