JUNCOS 463 



of the birds have their nesting well under way. Our earliest record of 

 a completed nest with eggs was made on June 10 (1915) at Chinquapin. 

 But earlier instances will doubtless be found upon further search; for 

 we saw a bird carrying nest material on May 20 (1919). The peak of 

 nesting activity is reached in June, during which month, in 1915, we 

 found, without special search, over a dozen nests. The first young noted 

 out of the nest in that year were observed in Yosemite Valley on June 21, 

 soon after which new broods were common. But nesting does not cease at 

 an early date. Either some pairs are delayed, through accident or other 

 cause, or else they rear more than one brood. A nest found at Merced Lake 

 on August 20, 1915, held two young not old enough to fly ; and bob-tailed 

 youngsters were seen near Washburn Lake on August 24 the same year. 



The majority of the nests observed were located either at the margins 

 of wet meadows, or along open creek banks. The birds seemingly prefer 

 to be able to fly to and from the nest unimpeded by vegetation. The nest 

 is a compactly woven cup, about three inches in outside diameter and the 

 same in depth. It is almost invariably sunk in the ground so that the 

 rim is flush with the surface. Sometimes it is placed at the side of a log 

 or beneath a fallen branch, but as often it is on open ground amid the 

 grasses, and one nest was seen in the center of a traveled road. As an 

 exception to the general rule may be cited a nest placed on an overhead 

 beam under the roof of a painted cottage porch in Yosemite Valley. This 

 nest was bulkier than usual, and the materials composing it straggled down 

 the side of the beam. It was evidently built in good faith because two 

 eggs were laid ere a gust of wind cast it to the ground. 



The average nest is composed largely of small plant or grass leaves 

 and stems compactly woven together. The larger pieces are on the out- 

 side, and the size of the pieces of material gradually decreases as the center 

 is approached. The inside lining is usually of horse hair, but occasionally 

 shed hairs from some of the native mammals are used. Four is the usual 

 number of eggs laid and no more than this complement were seen in any 

 nest examined by us. Sometimes but three seemed to constitute the com- 

 pleted set. 



During the summer the members of a pair of Sierra Juncos keep in 

 close company, and if the vicinity of their nest is approached the tAvo 

 will often exhibit a high degree of concern. If the female is incubating 

 she will usually leave in a flurry, with the tail widely spread (whereby 

 the eye catches the white quickly), and then trail along the ground, giving 

 an appearance of being injured in an effort to focus interest upon herself 

 and draw attention from the nest. Soon the male, if not already at hand, 

 will appear and the two will hop excitedly about either on the ground or 



