1914] (Jri iiiicll: Mammals and Birds of the Colorado Valley 215 



willows. It did not, however, seem to visit water, and so its presence 

 did not at all depend upon the proximity of the river. 



April 19, on the California side, eight miles east of Picacho, a nest 

 was found in a smoke-bush (Dalea) . It was four feet above the ground, 

 of usual structure, and contained five small young. April 23, on the 

 same side, four miles above Potholes, a brood of nearly grown young 

 was flitting about at large. The breeding time in this region is thus 

 indicated. 



Hylocichla ustulata ustulata (Nuttall) 

 Russet-backed Thrush 

 As elsewhere in the west this bird proved to be a late arrival. The 

 first individuals were noted May 4 and 5, five miles northeast of 

 Yuma, one each day. On both sides of the river in the vicinity of 

 Pilot Knob, May 9 to 15, the species was of frequent observation, 

 chiefly at daybreak in the willows close along the river. One was 

 seen, however, in a rocky ravine on Pilot Knob itself, towards late 

 evening of the 14th. The species is most certainly only a transient 

 through the region. The three specimens taken (nos. 13850-13852) 

 are unequivocally referable to II. u. ustulata. 



Hylocichla guttata guttata (Pallas) 

 Alaska Hermit Thrush 

 Hermit thrushes proved not to be characteristic winter visitants, 

 as expected, and they were rare even as migrants. Unmistakable notes 

 of one were heard at daybreak from a willow thicket in Chemehuevis 

 Valley, March 9. Heard again similarly, ten miles below Ehrenberg, 

 March 31. A single individual secured (no. 13853) on the California 

 side twenty miles north of Picacho, April 10. This bird, the last of 

 the species noted, was in a dense willow growth close to the river. 

 The specimen is identical, in size and coloration, with examples of this 

 race from the Prince William Sound region of Alaska. 



Hylocichla guttata nanus (Audubon) 



Dwarf Hermit Thrush 



There is in the Museum a skin (no. 6432) taken by J. G. Cooper at 



Port Mohave, January 25, 1861. Although obviously faded on its 



ventral surface, by size and dorsal color this specimen is distinctly 



referable to nanus. 



