1118 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



pen in the Canadian Life Zone of the Arizona White Mountains: 

 "Steadiness, quahty and variety suggest j^^^^^^onotus: Tswee tswee 

 tsee tswee chit chit chit chit. There was another series of tsuwee tsuwee 

 tsuwee tsuwee chit chit chit chit and one of just six chits." 



While the junco characteristically sings from tall trees in spring, it 

 occasionally uses lower perches. One of a pair of caniceps I watched 

 at timberline in Colorado June 24, 1958, sang on the ground as it 

 foraged and occasionally from a twig a foot or two above the ground. 



At Flagstaff, Ariz., in the Transition pine forest at 6,900 feet, L. L. 

 Hargrave (MS.) in 1936 recorded the earliest territorial songs of two 

 dorsalis, one February 14 and the other March 3. The next year he 

 heard juncos (perhaps Oregons instead of "red-backs") singing a "soft 

 twittering song, very faint — not heard far" on February 4; the first 

 territorial song by a dorsalis, he heard the same date as the preceding 

 year — February 14. E. C. Jacot (MS.) at Alpine, southeast of and 

 1,100 feet higher than Flagstaff, recorded the gray-headed junco, 

 probably both subspecies, singing "since the 11th" of March 1935, when 

 there were 10 to 15 inches of snow on the ground, with open patches 

 at bases of trees and along streams and roads. On March 18, Mr. 

 Jacot recorded of caniceps: "At Alpine as usual. Seem to be in full 

 song," and of dorsalis: "red-backed in full song. They and gray- 

 headed seem to sing almost as soon as they are perclied in tree or 

 bush after being flushed." The latest dorsalis singing dates also are 

 from the White Mountains. F. G. Watson (MS.) at the Phelps 

 Ranger Station at 9,400 feet heard them "singing about the cabin 

 each day" July 9 to 28, and also on Baldy Peak at timberline, 11,200 

 feet, July 12. Thus the period of singing by dorsalis in 1936 included 

 nearly twenty-three weeks — February 14 to July 28. 



My earliest seasonal record for singing by caniceps in Colorado is 

 Mar. 15, 1951, in its breeding habitat at 7,500 feet. On May 2, 1954, 

 none of approximately 15 caniceps at the edge of the foothills at 6,000 

 feet, driven down from the mountains by a severe snowstorm, was 

 heard to sing, although 7 weeks earlier on March 13 in 1955, at the 

 same place several individuals of a mixed flock of approximately 35 

 J. 0. monianus, J. o. mearnsi, and J. hyemalis (no J. caniceps) were 

 in song. On May 21, in both 1955 and 1960, two of seven or eight 

 birds seen each time in the Hudsonian Zone at 11,000 feet were, 

 singing, although 2 to 3 feet of snow delayed nesting 4 or 5 weeks 

 During a 5-year population study in ponderosa pine (Thatcher, 1956) 

 the latest singing date was July 17, 1955, when the male of only one 

 of six observed pairs sang. A few days earlier on July 12 in 1952, 

 four of seven were in song. My extreme latest song dates are July 31, 

 one in a cool aspen forest at 7,750 feet and one of eight adults at 

 timberline, 11,700 feet. The song period of caniceps thus is approxi- 



