212 University of California Publications in Zoology [Vol.12 



always within a limited radius of nests. As far as observation went, 

 these birds do not need to visit water; some were met with as much 

 as three miles away from the river up desert washes. 



Nests containing eggs or young were found as follows: April 5, 

 California side opposite Cibola, eggs four, incubation advanced ; April 

 7, Arizona side ten miles below Cibola, eggs four, incubation far 

 advanced; same date and place, three eggs incubated and one newly 

 hatched young; same date and place, eggs five, incubation nearly 

 complete; April 11, California side, twenty miles above Picacho, eggs 

 four, incubation advanced; April 12, same place, three small young 

 and one egg about to hatch; April 22, on the Arizona side five miles 

 above Laguna, a brood of two-thirds grown young was encountered. 

 The breeding period thus would appear to be of remarkable uniformity 

 among all individuals of the species. 



The above six nests varied from 38 to 96 inches above the ground, 

 averaging 69 inches. These, of the usual firm-walled, globular type 

 and constructed of stiff, thorny twigs, with the laterally placed opening 

 scarcely larger than the diameter of the bird, would thus appear 

 admirably adapted for the exclusion of the parasitic cowbird, of much 

 greater size, as well as a defence against depredators of various sorts. 

 I can see no other reason for so specialized a structure. Yet the 

 plumbeous gnatcatcher, occupying almost an identical range, and with 

 open nests, lays the same number of eggs, as though it were no more 

 subject to fatalities than the verdin. This is true also of the Sonora 

 yellow warbler (see Brown, 1903, p. 47). 



A series of twenty-four verdins was taken, nos. 13922-13945. Two 

 of our specimens, taken at Needles February 15 and 16, are much 

 discolored with coal soot. 



Besides these, there are in the Museum collection five specimens 

 (nos. 4238-4242) taken in 1861 by J. G. Cooper at Fort Mohave. The 

 dates of capture are: February 19, March 9, 15 and 30, and April 5. 

 These old skins are perceptibly paler than the freshly obtained speci- 

 mens, most probably due to their having been exposed to strong light 

 in a show case at some time or other. 



Regulus calendula cineraceus Grinnell 

 Ashy Kinglet 

 Evidently a characteristic winter visitant, as it was one of the com- 

 monest birds of the willow bottom in the vicinity of Needles at the 

 time of our arrival in the region, February 15. It was thenceforth 



