302 ANIMAL LIFE IN THE YOSEMITE 



Sometimes when excited they clicked their bills in the manner common to 

 most species of owls. Later in the season, when the young were out of 

 the nest, the adults would fluff up their feathers and strike their wings 

 against their sides, producing a 'plopping' sound. 



A nest seen on May 9 held 4 eggs in which incubation had begun. By 

 June 2 this nest held 4 young owls which were being brooded by the female 

 parent. Three were still in the natal down, but the fourth and largest 

 one had begun to acquire the gray feathers of the juvenile plumage. 

 When the nest was watched, both the parents attempted by the usual 

 tactics to distract the intruder's attention. These methods failing, the 

 female left the vicinity and did not return during the hour that Mr. Dixon 

 spent at the nest. 



This nest was again visited on June 22. By this time the young owls 

 were out of the nest and in Shepherdia bushes about a hundred yards 

 away. They had not yet learned to fly but were able to hop about readily. 

 They uttered low whining notes when the parent birds came to feed them. 



Another brood of young owls which was hatched about May 20 had 

 disappeared ten days later. Either they had been blown out of the nest 

 by the hard winds of the intervening days or, perhaps, they had fallen 

 victims to the ever present magpies. The latter were always about the 

 owl nests while the old owls were incubating, and it seemed as though the 

 parent birds would have to guard their treasures vigilantly in order to 

 prevent the magpies from destroying the eggs or young. 



In one instance, after the young of a brood were partly grown, one 

 of the owlets was picked up in the hand. At this the female parent, in 

 the top of a 15-foot willow near by, let out an "agonized, blood-curdling 

 squawk," and allowed herself to fall down through the thicket to the 

 ground, where she fluttered with a well-feigned semblance of injury. 



Upon summarizing the nesting data gained at Williams Butte, we find 

 that of the 7 nests or broods examined 3 were of 5 eggs or young each, and 

 4 were of 4. All the nests were in willow or Shepherdia thickets. All sets 

 of eggs were complete by May 1, one had hatched by May 6, and one had 

 not hatched by May 17. The individual records follow : 



No. 1. April 27, 5 eggs; later deserted. 



No. 2. April 29, 5 eggs; later destroyed. 



No. 3. April 30, 4 eggs. 



No. 4. May 6, bird on 2 downy young and 2 pipped eggs. 



No. 5. May 9, 4 incubated eggs; June 2, 3 small young in down and 1 larger 



young one with flight feathers partly out; June 22, young out of 



nest and in thickets near by. 

 No. 6. May 15, 4 young with ear tufts and wing quills beginning to grow out; 



May 18, about half-grown (pi. 42b); June 1, out of nest. 

 No. 7. June 27, brood of 5, with both parents, encountered together in willow 



thicket. 



