1108 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 2 



gullies. Nests tend often to be somewhat "tunneled" into the ground, with 

 only a very small aperture for the entrance and exit of the bird. 



The outside of the nest is usually composed of coarse grasses and old decayed 

 leaves; the inside is of finer grasses and always lined with some type of hair or 

 feathers. Dr. Horace Quick helped me identify hairs from a number of different 

 nests. We found not only the usually cited cattle and horse hairs, but also cervid 

 hairs of either deer or elk, dog hairs, human hairs, hair from a snowshoe hare in 

 winter pelage, and both fur and guard hairs of squirrels. 



The nesting of dorsalis is similar to that of caniceps, but generally 

 starts earlier in the spring, for this race winters either within or 

 much nearer its summer range than does caniceps. Hargrave (1936) 

 saw a dorsalis carrying nest material at Flagstaff in northern 

 Arizona, Mar. 24, 1935. The first brood left a nest in a vine 

 at the same place, according to Katherine Bartlett (MS.), on Apr. 28, 

 1940. E. C. Jacot (MS.) saw a dorsalis in the White Mountains of 

 Arizona, at 8,000 feet elevation, Apr. 7, 1935 "carrying nesting 

 material — a pine needle." Probably the latest recorded nesting date 

 for dorsalis appears in F. M. Bailey (1928): "* * * On August 17, 

 1919, a nest with eggs was found 30 miles southwest of Chloride in 

 southwestern New Mexico * * * at 7,200 feet (Ligon, 1916-1918)." 

 Assuming a requirement of at least 30 days after hatching for com- 

 pletion of breeding activity, this would extend the nesting season for 

 dorsalis over a period of 25}^ weeks, March 24 to September 17, 4 or 

 5 weeks longer than that of caniceps. 



Of dorsalis nesting in northern Arizona, Mearns (1890b) says: 



Sets of fresh eggs were found from May 22 to July 22, 1887, the nesting season 

 varying considerably with the altitude, but the clutch seen on the last date 

 probably belonged to a second brood. A typical nest was found on May 30, 

 1887, in pine woods near the bottom of a ravine on Mormon Mountain. At a 

 short distance was a deep snow-bank. The male parent flew from the nest, 

 beneath my horse's feet, where I found it concealed in a thick bunch of wire-grass. 

 It was composed of fine roots, stems of plants, grasses, and an occasional feather, 

 loosely put together in the manner of most ground nests. It contained four 

 eggs * * *. 



I found its nest close to the upper edge of timber on San Francisco Mountain 

 about the middle of June, and another nest on the very top of Baker's Butte 

 [8077 feet], containing eggs, on the 22nd of July. 



F. M. Bailey (1928) describes a dorsalis nest: "A typically well 

 concealed nest of the Red-backed Junco found by Mr. Ligon in the 

 Chloride region was hidden under a small pine that had spread 

 over the ground and caught dead leaves, making a thick supporting 

 mat as well as a dark base for the inconspicuous nest of bark and 

 dead grass with its slight lining of hair. To further protect it from 

 prowling enemies, a small bowlder [sic] stood beside it, blocking the 

 entrance." Mrs. BaUey (1927) mentions that dorsalis also nests 

 "in clumps of oaks on hillsides," as does W. I. Mitchell (1898): 



