1026 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



a few minutes they all flew up into the nearby pines together. While 

 on the ground, they all moved slowly in the same direction, hopping, 

 picking up two or three bites, and then hopping agam. 



White-winged j uncos have often been noted around feeding stations 

 well after sundown. Mrs. Grace Mclntyre (pers. comm.) comments 

 that they have fed around her banding station at Devil's Tower, Wyo., 

 long after twilight. Individuals I have banded and released after full 

 darkness have, in contrast, seemed unable to find their way to suitable 

 roosts. I have not yet exactly determined the minimum intensity of 

 light juncos require for feeding, 



Alden H. Miller has pointed out (pers. comm.) that the white- 

 winged junco seems less active than smaller juncos, but that basically 

 its habits are similar to theirs. 



The general impression of winter flocks is that the birds tend to act 

 as a compact unit. Close watching, however, shows that a definite 

 pecking order exists, and that when two individuals are within peck- 

 ing distance the dominant one lunges at the other without moving 

 from his place. I have noted this often at banding traps, where one 

 individual invariably defends the entry platform from all the others. 



My observations concerning tolerance of other species are limited. 

 Oregon and slate-colored juncos are the most intimate associates of 

 white-wings in the winter flocks of the Black Hills. Oregon juncos, 

 though smaller, may drive white-wings away from a feeding station. 

 Other wintering passerines, such as black-capped chickadees and white- 

 breasted nuthatches, often feed with junco flocks, but seldom so 

 closely that one tried to drive another away. Juncos usually scatter 

 when flocks of pinon jays arrive at the feeding station. 



When removed from a banding trap, most white-wings are passive, 

 but some wfll attempt to peck the bander's fingers if they are held 

 directly in front of the bird's bill. Their reactions are intermediate 

 between those of the very passive pinon jays and the very pugnacious 

 black-capped chickadees. 



Voice. — White-winged juncos in flocks seem to communicate with 

 each other by a high musical squeak consisting of a single note. I 

 heard this note used frequently by a flock of 10 juncos foraging around 

 my banding trap during a heavy snowstorm. 



Another frequent winter call is a single chip, similar to that of the 

 slate-colored junco, but more musical. It seems to be more of an 

 alarm note, while the squeaking note seems to be used in proclaiming 

 intra-flock dominance. 



True singing is apparently confined to spring and early summer. 

 Peterson (1961) describes the song as "a loose musical trill, similar to 

 the songs of other juncos." To me, it sounds very much like the song 

 of the chipping sparrow, but somewhat more musical and variable. 



