1008 U.S. NATIONAL MUSEUM BULLETIN 23 7 pabt 2 



when the bush was hit with a stick." Finally the bird was forced off 

 and it then ran 25 feet over the ground with the tail elevated. Again 

 on June 6 he "had to shake the bush violently before the bird would 

 leave." On the last visit to this nest at 9:00 a.m. on June 9, the 

 young were hatching; one gaped for food; one was stUl lying in part 

 of the shell and the third egg was unhatched. The incubation period 

 was thus about 13 days, assuming that incubation started on May 26 

 when the sparrow was flushed from two eggs. 



James B. Dixon wrote me also of a sage sparrow that would not flush 

 until the nest bush was struck. All observers emphasize that the incu- 

 bating bird normally flushes by dropping to the ground and running 

 off. I noted in Oregon that the female ran quietly within 25 feet of us, 

 holding the tail up, thrasherlike. Usually the parent is silent, or it ut- 

 ters the rather faint tsip alarm note, and then finally may alternate 

 running on the ground and calling from bush tops, jerking the taU up 

 periodically. 



Eggs. — The sage sparrow lays three or four eggs, rarely five. Spe- 

 cific records in the literature and data in the Museum of Vertebrate Zo- 

 ology for what are apparently completed clutches show 12 sets of three 

 and 10 sets of four. There are two records of five, one by William 

 Leon Dawson (1909) and the other by Gabrielson and Jewett (1940). 



The eggs are ovate. The ground color is pale blue or bluish white 

 and the surface is speckled, spotted, and often blotched with "Verona 

 brown," "rood brown," or "wood brown"; occasionally black dots and 

 lines occur; undermarkings are "light neutral gray." Spottings may 

 be scattered over the entire surface or concentrated toward the large 

 end, sometimes forming a crude wreath. On some the brown mark- 

 ings are sharply defined, whereas on others they are clouded and con- 

 fluent. Thus there is considerable variation; frequently the under- 

 markings are lacking while in others they may be dominant and the 

 brown spots pale and few. 



The measurements of 70 eggs average 19.47 by 14.56 millimeters. 

 The eggs showing the four extremes measure 21.2 by 14.9, 19.6 by 16.2, 

 18.2 by 15.1, and 18.8 by 13.7 millimeters. 



Young. — The sage sparrow's young have pale natal down in general 

 correlation with the prevailing paleness of the nest lining and the some- 

 what exposed nest location, as pointed out by Jean M. Linsdale 

 (1936b). Young are fed insects by the adults, as generally is true in 

 sparrows of the subfamUy Emberizinae. J. M. Linsdale (1938) 

 watched an adult feeding a bob-tailed young on the ground, the fledg- 

 ling being able to fly distances of but 3 feet. "The parent moved 

 about, jerking its tail upward slightly, as it picked up insects, within 10 

 feet of the young one" that was skulking under an Atriplex bush. An- 

 other adult, evidently the male of the pair, sang near by. 



