JAYS 385 



small birds. And the small birds have known this, evidently for genera- 

 tions, because they almost universally announce with unmistakable tones 

 of anxiety the presence of a Blue-fronted Jay near their nests. The 

 period during which this instinct of blue jays is exercised coincides of 

 course with the nesting season, when eggs or young of the other birds are 

 available and when the jays themselves have broods or mates to feed. At 

 other times of the year the jay and its smaller relatives live in peace. 

 We, ourselves, while in the Yosemite region, did not chance to see one 

 actual instance of plundering by this jay; such observations can come 

 but rarely even to a person on the lookout for them. But we have observed 

 cases elsewhere, and we know of many reliable reports of the depredations 

 of this jay. We saw evidence of a circumstantial nature, and some of this 

 is worth while relating. 



In Yosemite Valley on June 1, 1915, our attention was attracted 

 to a Blue-fronted Jay which was beset by an angry Western Warbling 

 Vireo and then by a Cassin Vireo in similar mood. Each evidently 

 suspected the jay of sinister intention and each in turn endeavored to 

 drive the larger bird away. At Chinquapin, on June 14, 1915, two Red- 

 breasted Nuthatches were heard calling wd, wci, wd, in excited tones. Fol- 

 lowing up the noise, we found their attention to be centered on a pair of 

 Blue-fronted Jays. The latter were perfectly quiet, a mannerism for 

 which the marauders are noted when on their plundering expeditions. 

 On the same day a Ruby-crowned Kinglet was heard calling its yer-riip, 

 yer-t^up, yer-rup, over and over again in low but insistent tones. It, too, 

 was concerned over a pair of the silent but insidious jays. When one of 

 the latter was shot the kinglet immediately broke into song! At Mono 

 Meadow on June 22 some anxious bird notes were heard coming from 

 the top of a lofty red fir. These, again, proved to be due to the presence 

 of a pair of Blue-fronted Jays in the neighborhood. In this instance there 

 were at least 11 small birds at the scene of the disturbance. A pair of 

 Western Warbling Vireos seemed to be the ones most intimately concerned 

 and their calls had evidently attracted the other birds to the site. ' ' Those 

 present" in addition to the vireos were two Wright Flycatchers, two 

 Western Tanagers, two Audubon Warblers, a Red-breasted Nuthatch, and 

 two Ruby-crowned Kinglets. All were contributing their voices to the 

 clamor of remonstrance against the jays. Near Bower Cave, on May 13, 

 1919, a pair of Willow Woodpeckers was seen mobbing a pair of 

 Blue-fronted Jays, while a California Woodpecker offered half-hearted 

 sympathy. The first-named were uttering in monotonous succession their 

 high-pitched call notes. 



Because of the depredations of the Blue-fronted Jay among the smaller 

 song birds of the Park, the rangers, under the direction of the Park 



