376 University of California Publications in Zoology. [Vol. 7 



Two nests were discovered, the first on July 1 at the head 

 of Big Creek in an aspen thicket. The nest was built against a 

 large limb, being supported by two smaller branches and fastened 

 with sheep 's wool. It was three and a half feet above the ground, 

 its cavity being 53 mm. (2%o inches) in diameter and 38 mm. 

 (1% inches) deep. The nest contained four eggs in so late a 

 stage of incubation that their preservation was impossible. The 

 second (found July 9 on Big Creek, altitude 7000 feet) was in 

 process of construction. The body of the nest was being built 

 up of thin strips of quaking aspen bark, and its fastenings to 

 the limb were of spider-web. It was about half completed; no 

 lining had as yet been put in. The nest was four feet above 

 the ground. The female was carrying on the building process. 

 She came three times during a few minutes, and, while sitting 

 on the nest, added material with her beak, all the while uttering 

 a series of "ker-wit" call-notes, and occasionally notes of dif- 

 ferent inflection. The male bird was shyer and more quiet. He 

 was not observed aiding in the work of construction. 



Otocoris alpestris merrilli Dwight 



Dusky Horned Lark 



Distribution. — Occurred at nearly all the lower stations 

 visited, following up the broad Leonard Creek flats to 7000 feet. 

 Its habitat thus falls within Upper Sonoran and Transition. 



It is perhaps significant to note that certain of our observa- 

 tions with reference to the distribution of this bird do not accord 

 with those of Eidgway (1877, p. 499). In our experience, 

 instead of being omnipresent, equally abundantly in all locali- 

 ties, the horned larks exhibit a very marked preference for the 

 vicinity of the fields and dry meadows, as along Quinn River. 

 The birds were frequently encountered, however, on the most 

 inhospitable deserts, although they were more numerous in 

 pleasanter surroundings. We did not observe them at a greater 

 altitude than 7000 feet, although Ridgway noted them as high 

 as 11,000 feet. 



Habits. — The mode of fiight is quite characteristic. The 

 wings are vibrated rapidly a number of times in alternation with 

 short periods of soaring. 



