390 ANIMAL LIFE IN THE YOSEMITE 



The nest mentioned above as found near Lagrange on May 8, 1919, was 

 in a blue oak on the crown of a rounded hill overlooking the Tuolumne 

 River. The rim of the nest was by actual measurement 4780 millimeters 

 (about 16 feet) from the ground, and was at the side of a horizontal branch 

 80 millimeters in diameter where some small twigs formed a 5-sided frame 

 into which the nest was set. The foundation work of the nest was about 

 200 millimeters across, and consisted of crooked dry blue oak twigs. There 

 were large interstices in the weaving. Inside of this was an intermediate 

 layer of dry fine yellow grass stems and rootlets. And within this was 

 a thin lining of black horsehair forming an inner cup. The latter was 

 100 milKmeters in diameter at the top and 50 millimeters deep at the 

 center. The four eggs lay on this inner lining. One of the parent jays 

 had been sitting on the nest, which was readily visible from anywhere 

 within a 50-foot radius of the tree; but the bird flushed at our approach 

 and did not again come within a hundred yards of the site while we 

 were there, although both members of the pair called from a distance 

 several times. 



Soon after arriving at Blacks Creek, west of Coulterville, in 1919, we 

 discovered a California Jay's nest in the crotch of a Avillow which leaned 

 over the creek directly opposite where we had made our camp, and not over 

 30 feet from the tent door. During the succeeding days we had many 

 opportunities to observe the behavior of the parent birds. When one of 

 us climbed to the nest on May 10, it was found to contain one newly 

 hatched youngster and 3 eggs ready to hatch. The sitting bird had 

 remained until closely approached. It then flushed quietly and returned 

 as soon as the observer quitted the tree. The mate was seen only momen- 

 tarily on this occasion. The remaining eggs evidently hatched on that 

 day or the next, as the adults had by that time begun to busy themselves 

 in obtaining food and bringing it to the nest. 



The parent birds had a particular route in approaching and leaving 

 the nest, and this route was adhered to strictly. They would always 

 approach through the trees of a wooded slope to the east, and then, having 

 reached the nest tree, hop by easy stages to a position on the west side 

 of the nest. From there the nestlings would be fed, and then the nest 

 cleaned. After that the bird would work out of the south side of the 

 willow, fly to a digger pine across the creek immediately above our tent, 

 hop upward until near the top of the pine, and from there would take off 

 in a direct course to its next forage ground. Even when the jays had 

 been hunting insects in the open area immediately west of our camp, they 

 would circle about when ready to return to the nest and approach it from 

 the east. Only one adult visited the nest at a time although they often 

 followed one another in quick succession. Save for the low crooning given 



