586 U.S. NATIONAL MUSEUM BULLETIN 237 part i 



Young. — On June 2, 1956, we were able to observe the hatching 

 of the young and their development through the first week. At 8 :00 

 a.m. on June 2, two eggs had hatched and the third was pipped. 

 When the nest was revisited about six hours later, the young of the 

 third egg was dead half out of the shell and the fourth egg was pipped. 

 By 7:30 p.m. the fourth egg had hatched successfully. The empty 

 shells are removed apparently soon after hatching, though we were 

 unable to observe the process. 



The young at hatching were naked except for a few down feathers 

 along the spinal and capital pterylae. The day after hatching the 

 feather papillae had darkened and enlarged noticeably. By the 

 third day the sheaths were emerging, especially on the wings, and by 

 the sixth day they had begun to open. In common with most pas- 

 serines, the growth of the young towhees is very rapid. The weight 

 of these nestlings increased about fourfold during the six days of 

 observation. 



Brooding is seemingly entirely by the female. At first her periods 

 off the nest are brief, but they become more sustained by the fourth 

 or fifth day. Feeding the young is apparently largely the responsibil- 

 ity of the male. On June 6 a male was observed to feed the young six 

 times during a 160 minute period. Each time he approached the nest 

 he gave the pshew call, softly and muffled by the food in his beak. 

 The female left the nest immediately and he fed the young. After 

 feeding them he usually returned to his perch to sing for awhile before 

 setting out to scratch for food and feed the young again. 



Voice. — In addition to the spring song of the male, which shows 

 considerable variation from individual to individual, the spurred 

 towhee has two distinct calls which vary but little and are used by 

 both sexes. The first of these we designate as the tseep note. The 

 female gives it as she approaches the nest containing young, and it is 

 the first sound the young make. It is not very loud, and can be heard 

 only at distances of a few feet. It is heard most commonly during 

 the winter as the birds move about through the shrubbery and under- 

 brush. 



The pshew call is uttered commly by both sexes at all seasons. This 

 is a scolding call, and usually indicates disturbance of some sort, but 

 it may also be heard when the birds are feeding and apparently un- 

 excited. At the close of a period of vigorous singing, the male will 

 often fly down into his shrubby habitat and call pshew steadily for a 

 considerable period. Frequently, and especially during the mating 

 season, the pshew call is answered by several nearby males. 



The spring or mating song, given by the male only, consists of one 

 to five introductory notes followed by a trill usually higher than the 

 introductory tones, sometimes at the same pitch, more rarely at a 



