66 BULLETIN 17 4, UNITED STATES NATIONAL MUSEUM 



The downy is not forced to seek the sun and warmth and the 

 inexhaustible food of the Tropics, for the woodlands of New England 

 and southeastern Canada are stored with food that, with a roosting 

 hole, enables the bird to withstand the severest winter. But this 

 food is limited; the insects that have been multiplying all summer, 

 thus adding continually to the woodpeckers' supply of food, stop 

 multiplying when the frosts come, and will add no more until 

 spring. 



The downy is not a bird that ranges widely in search of food; 

 moreover, for protection against the weather it is held to the vicinity 

 of its roosting hole. Therefore each bird, in order to be sure of 

 sufficient food for itself during the cold months, must maintain 

 dominion over a territory large enough to support it through the 

 winter. 



Thus it comes about that in autumn the downy does perforce 

 change its habits, or rather its attitude toward other birds of its 

 species. The families disperse, and until the next breeding season 

 each individual becomes a solitary bird, living in a restricted region, 

 which it defends against trespass, resenting and repelling the 

 approach of any other downy woodpecker. 



This reversal of attitude or character — the change from a member 

 of a family to an anchorite in fall, and back again in spring — takes 

 place gradually, we may suppose, and not exactly at the same time 

 in every bird. Hence one bird meeting another in autumn, while the 

 change is in progress, may underestimate the degree to which it has 

 drawn away from its fellows, or, in the spring, may overestimate the 

 amount of cordiality that has returned to the wintering anchorite. 

 This lack of understanding may give rise to behavior difficult or 

 impossible for us to interpret. 



Sometimes the relationship between two downies is clear enough, 

 as when, on September 20, 1910, I saw a male fly repeatedly at a 

 female in a menacing way and drive her off ; and when on November 

 3, 1935, I saw a female bird fly toward a male, which was perched 

 near a hole in an electric-light pole, from which he did not retire, 

 as a perched bird commonly does when approached by a bird on the 

 wing, but held his ground while she flew away ; and when Lewis O. 

 Shelley (MS.) tells of a female bird "rushing with antagonistic atti- 

 tude at her two daughters" and also driving off her granddaughters 

 whenever they invaded her winter territory in autumn, all these birds 

 being identified by bands. 



There are cases, however, in which the relationship between the 

 birds is very puzzling. In the following scene, from my notes, there 

 is a hint of hostility or remonstrance, but a suggestion of courtship 

 also — out of place, it seems, in autumn between two female birds. 

 "October 15, 1935. Two birds are in a large, bare maple tree; one 



