NUTTALL'S WHITE-CROWNED SPARROW 1311 



'D, E flat, E-F, B flat' settles nothing, and is an endless musical argument . . . 

 variations on a theme. But the singing of the song 'G, C-C-C, D-D, B' and its 

 response 'B, D, E flat — E natural, C completes a musical sentence ending with 

 a cadence (a return to the tonic). Even so, the birds go on singing it over and 

 over again, a characteristic of birds but not of human musicians. 



Twilight singing, especially morning twilight, with its greater proportion of 

 duets and of unusual versions of the songs, was very interesting. If any origi- 

 nality of melody or any creative singing was possible, I believe that it occurred 

 then. But if the birds were drawing upon a set of traditional tunes, they made 

 aesthetic choices of rhythmic and melodic details within their songs, particularly 

 when two birds were singing together in antiphonal duet. 



Behavior. — As all the sections under "Habits" fall properly under 

 the heading of "Behavior" in the broadest sense of the term, only a 

 few mannerisms that distinguish white-crowned sparrows from other 

 species likely to be found in the same habitat are mentioned here. 

 One of the habits of winter flocks of white-crowns is to forage on the 

 ground by roadsides. When disturbed, they fly or hop up and plunge 

 over the embankment into the nearest cover. If the flock is large, 

 the individuals may move almost as one bird. The essential feature 

 of this escape reaction is the force with which they make a dash for 

 the nearest cover. So characteristic is this behavior that one can use 

 it as a diagnostic field character when traveling at high speed. Grin- 

 nell and Storer (1924) describe the ensuing behavior as follows: 

 "If a flock of white-crowns is come upon while it is foraging on the 

 ground, the birds get up quickly and dart into the shelter of some 

 nearby thicket, each pursuing a separate course. There they remain 

 for a short time, silent and motionless, but peering furtively at the 

 intruder. After a short period of quiet, if there be no further cause 

 for fright, they become active again, giving voice to faint seeps and, 

 individually, they begin to hop up in the brush where they can see 

 about before venturing into the open again." 



Ralph Hoffman (1927) describes another trait of winter flocks: 

 "When individuals of the flock disagree about a resting place they 

 utter little confused squabbling notes, and just at dusk, when birds 

 settle in thick trees for the night, and at dawn, they repeat for several 

 minutes the alarm note, a metallic pink." 



Field marks. — Adult white-crowned sparrows are distinguished by 

 the high, puffy crown, broadly striped with black and white, and by 

 the clear pearly-gray breast. The sexes are alike, but females usually 

 look somewhat duller, that is, the contrast between black and white 

 stripes is not so striking as in the male. Immature birds are buflier 

 than adults, with head stripings of dark red-brown and light buffy- 

 brown instead of black and white. Ralph Hoffman (1927) writes: 



"No other bird can be confused with an adult sparrow of the 

 White-crowned group, if the markings of the head are seen. Imma- 



