J UNCOS 461 



It is during the fall and winter months that individuals of the Slate-colored 

 and Shufeldt juncos are occasionally encountered in flocks of the Sierran 

 birds. These have probably traveled all the way from summer localities 

 in British Columbia and beyond. 



In the fall of 1915 we remained in Yosemite Valley through the first 

 real snowfall of the season which began on the evening of November 8 and 

 continued into the following day. On the morning of the 9th juncos were 

 in active migration down the Valley. They did not fly along continuously 

 nor did they alight in the snow, but from the clear ground about the base 

 of one thick-foliaged tree they dashed on a few rods to another similar 

 shelter and hopped about there for a minute or so before moving farther. 

 Each individual was moving independently, yet all in the flock were going 

 in the same general direction. One bird would fly ahead, loiter a minute, 

 and be passed by others previously left behind, and so on. At any one 

 point there would be a rapid succession of juncos w'hile the flock as a 

 whole moved more slowly. It was quite evident that the birds from the 

 plateau above the Valley were migrating down-slope and westward, as 

 more juncos were seen on that morning passing one place on the north side 

 of the Valley than had been seen all told in the preceding month on the 

 whole floor of the Valley. 



On December 26 and 28, 1914, when the early snows of that season 

 had largely melted off on the north (sunny) side of the Valley, several 

 companies of juncos were observed there, and it is possible that ameliora- 

 tion of conditions had led them to come in again from the westward. 

 Some of the birds were around the buildings of the old Presidio, foraging 

 far back within the open basements. Subsequently, a resident of the Valley 

 reported that about 25 juncos had stayed around his house during the 

 winter of 1915-16, as he thought, because of the food continually put out 

 for them. 



In general demeanor the junco is more active than many of the spar- 

 rows. On the ground it gets about with quick movements, turning first 

 to one side and then the other, but not often hopping many paces before 

 stopping to examine its surroundings. It does little scratching, and indeed 

 neither its claM's nor its bill are of the stout type found in birds such as 

 the fox sparrows which dig out their food. The Sierra Junco, like the 

 Western Chipping Sparrow, is a surface forager and gets its provender 

 by moving about rapidly and scanning a relatively large area of ground. 

 This is as true of the members of a winter flock as of indi^-idual birds in 

 summer. 



When frightened, a junco flies directly to cover, taking shelter usually 

 within trees or large bushes. Its general procedure is to fly along a short 

 distance above the ground, usually reaching the nearest foliage at the first 



