398 ANIMAL LIFE IN THE YOSEMITE 



The roving habit of the Piilon Jay and its colonial nature are probably 

 both related to the marked preference of the bird for the seeds of the 

 piiion, which, for most of the year, form the staple article of its diet. The 

 crop of these nuts varies from place to place and from year to year ; so 

 that the jays must move about in order to find adequate sustenance. In 

 this search for food, the flocking tendency plays an important part, as 

 many eyes are better than two when the food supply is widely scattered. 

 In this respect the habits of the Piiion Jay recall those of the Band-tailed 

 Pigeon. 



Seeds of other pines are eaten when obtainable. An adult female 

 Piiion Jay collected on September 20, 1915, on the Mono Mills road close 

 to one of the Mono Craters had its throat crammed with seeds of the 

 Jeffrey pine, 28 by actual count. Since the cones of that tree were just 

 opening, the birds were afforded ready access to this source of supply. 

 The query arose as to whether the seeds in this jay's throat had been 

 gathered to feed her young which were to be seen near by, still in juvenal 

 dress though fullgrown, or whether she had intended to cache the seeds 

 somewhere against a time of want during the on-coming winter. 



On June 7, 1916, three families of Pinon Jays, with young barely able 

 to fly, were seen near Sand Flat, south of Mono Lake. The yoang birds 

 were being fed grasshoppers by their parents. The diet of the species 

 is thus varied to include insects, wherever this source is readily available. 



Cov^BiRDS. Molothrus ater (Boddaert)^^ 



Field characters. — Slightly smaller than female Eed-winged Blackbird, bill short and 

 thick, sparrow-like. Male with head and chest dull brown, plumage otherwise black with 

 a slight iridescence; female entirely dull brown, paler on under surface where faintly 

 streaked; no contrasted color markings in either sex. General habits of a blackbird. 

 Voice: So far as heard by us, a protracted squeal or high-pitched whistle, uttered by 

 male. 



Occurrence. — Found as a summer visitant in the Lower Sonoran Zone at Snelling and 

 near Lagrange (race ohscurus) ; also east of the Sierras, in the Transition Zone in the 

 vicinity of Mono Lake (race artemisiae) . One individual of the latter race was picked 

 up dead 3 miles north of Mount Bullion on December 27, 1917. Frequents stream-side 

 willow thickets and also stock corrals and pastures. 



Our first record of the Cowbird in the Yosemite section was made on 

 May 29, 1915, when a male of the Dwarf race was obtained at Snelling 

 after attention had been attracted by its high-pitched squeal. This bird 

 was perched at the tip of a tall dead tree standing within the dense growth 



22 Two species of Cowbirds are found in the Yosemite region. At Snelling and 

 Lagrange is found the Dwarf Cowbird, Molothrus ater ohscurus (Gmelin), while east 

 of the mountains in the vicinity of Mono Lake there is the Nevada Cowbird, Molothrus 

 ater artemisiae Grinnell. These two races differ chiefly in size, the former being smaller 

 throughout; but these differences can be determined only from specimens in hand. 



