1178 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



It is interesting to note that the songs of eight individuals recorded 

 in Mexico and analyzed by Marler and Isaac (1960) fall within the 

 range of variation Borror found in his recordings from the north- 

 eastern United States. 



Borror describes the songs of one individual which began with a 

 short series of long phrases and then abruptly went into a series of 

 short, more rapid phrases. For two seasons I observed a male at Lake 

 Itasca that had the opposite pattern. He began A\dth a series of rapid 

 short phrases and abruptly changed to a series of longer slow phrases. 

 The change was so marked that one observer concluded that two indi- 

 viduals were singing in the same tree. Forbush (1929) remarks that 

 "rarely a bird wdU interpolate or add some unusual improvised musi- 

 cal notes." 



Beginning with Audubon (1841) observers have noted that the 

 chipping sparrow occasionally sings at night, Mr. Bent recorded the 

 follo\\dng in his notes: "May 13, Dudley St., 10 p.m. Pitchy dark — 

 heard a chipping sparrow sing one strain." At Itasca State Park a 

 bird not infrequently sang a single song from the ridge of our cabin 

 roof at night. 



In a letter, A. A. Saunders wTites, "On a number of occasions, in the 

 very early morning, I have heard birds singing a series of short songs, 

 each one of eight notes, and each one beginning ^^^th a strongly ac- 

 cented note. This may be a sort of t\\'ilight song, but if so it is not 

 common." This may be the same song that F. H. Allen describes 

 when he writes, "The early morning singing of the chipping sparrow 

 consists of a rapid repetition of much shorter songs than the songs we 

 hear at other times. I have on at least one occasion heard this manner 

 of singing late in the afternoon." 



Field marks. — The two sexes are marked and colored alike. The 

 species may be readily distinguished from other Spizellas by the 

 reddish brown cap, the darker lower edge of which sharply dehmits 

 it from the whitish superciliary Hne, which is bordered below by the 

 black eye line. The plain underparts are gray to grayish white. 

 The bill is black. 



The song is most apt to be confused ^\^th that of the pine warbler. 

 Competent ornithologists have been misled by a chipping sparrow 

 singing in a pine warbler habitat. 



Enemies. — Statements on the importance of the cowbird as a factor 

 in limiting chipping sparrow population seem to vary considerabh^ 

 Friedmann (1929) lists it as one of the five species most commonly 

 parasitized in New York State. He reports "It is an extremely com- 

 mon sight to see one of these familiar little birds feeding a big, clumsy 

 Cowbird." In a study of nests in southeastern Michigan, Berger 

 (1951a), in a small sample of eight nests, had five parasitized, while 



