564 ANIMAL LIFE IN TEE YOSEMITE 



of the large slabs of bark. Both male and female were at work gathering 

 moss from the trunks of black oak trees in the vicinity and carrying this 

 material directly to the nest. When one of the birds entered the nesting 

 cavity it would stay but an instant, and so it seemed that little attention 

 was being given to the arrangement of the material at this, probably early, 

 stage of construction. 



A nest was seen in the Valley on May 31, 1911, in a crevice at the tip 

 of a burn on an incense cedar trunk. This was 14 feet above the ground 

 and scarcely 20 feet from the busy office of one of the large camps. Evi- 

 dence pointed to the presence of young. If young were there, the begin- 

 ning of nesting must have been close to the first of May. 



A nest of the Sierra Creeper which could be studied in detail was found 

 at about 4500 feet altitude near Indian Creek, below Chinquapin, on 

 June 11, 1915. It was in a fire-scarred incense cedar, which had a large 

 plate of bark sprung outward from the base of the tree. Behind this plate, 

 at a height of 7% feet from the ground, the nest was hidden. The space 

 between the bark slab and the body of the tree for a distance of 21 inches 

 below the eggs had been filled with loosely laid flakes of cedar bark, and 

 a few stray ends of these pieces of bark, projecting beyond the edge of 

 the crevice, had given the observer who had noticed one of the birds his 

 first clue to the exact location of the nest. The nest proper was a mass 

 of felted inner bark of willow, silvery gray in color, longer than wide, 

 about 4 by 2 inches, and was put together in more substantial manner 

 than the underpinning. There were 6 eggs in which incubation had just 

 begun. When the nest was first discovered the female was covering the 

 eggs, while her mate was gathering insects on a tree 30 feet away. As 

 the projecting slab of bark was lifted to gain better view of the nest, the 

 sitting creeper left and joined her mate. Then, while examination of the 

 nest continued, the two birds came down to as close as 8 feet from the 

 observer and voiced their wiry protests almost continually. 



As will have been inferred, the Sierra Creeper is an exceedingly local 

 bird, in that, having once selected a favorable neighborhood, it carries 

 on all of its activities within a very short radius. Indeed, at nesting time, 

 once an adult bird is seen, the observer may be confident of finding its 

 mate and its nest close by. The materials for the nest, and the food for 

 both parents and young, are gathered within a remarkably small circle. 



Slender-billed Nuthatch. Sitta carolinensis aculeata Cassin 



Field characters. — Size nearly that of Jimco; tail about half length of body. Top 

 of head and back of neck black or slate-black; cheeks and under surface of body pure 

 white; back slate gray. (See pi. lOe.) Runs about readily on bark of trees, moving 

 in any direction. Voice: Song a series of double notes all alike, cher-iver; call note a 

 nasal hanlc. 



