166 U. S. NATIONAL MUSEUM BULLETIN 211 



were in open situations often exposed to the sunlight, the dark lined nests were 

 in shaded places usually protected from direct sunlight. This contrast extended 

 also to the color of the down on nestlings. Nestling red-wings had conspicuously 

 whitish down, nestling Brewer blackbirds were decidedly blackish. These seem 

 fairly obvious examples of adaptions to exposure to sunshine — the whitish nests 

 and young to reflect sunrays, the dark ones to absorb them. Apparently it is 

 desirable for both the eggs and young birds to be thus protected. 



Nesting. — In general the nesting habits of the Nevada redwing do 

 not differ materially from those of other races of the species, the nests 

 being placed low down in tufts of grass, in marsh vegetation, in various 

 shrubs near water, or as high as 5 or 10 feet from the ground in willows. 

 Robert Ridgway (1889) "found a colony which had built their nests 

 in 'sage bushes' (Artemisia tridentata) growing in and about a shallow 

 alkaline pond, on Antelope Island, in the Great Salt Lake." J. S. 

 Rowley has sent me the following account of an especially dense 

 colony in an isolated locality: "I found an old reservoir on the desert 

 between Mojave, Kern County, and Little Lake, Inyo County, Calif., 

 on a deserted farm. Since there was no surface water for miles around, 

 these redwings had taken this place over. The tule patch was only 

 about 50 feet square and there must have been at least 200 nests 

 occupied there on April 19, 1934. I had to use great care in going 

 through the tules so as not to trample redwing nests." 



Eggs. — The Nevada redwing ordinarily lays four or five eggs, 

 probably more often four than five. These are indistinguishable 

 from eggs of adjacent races. 



Food. — E. R. Kalmbach (1914) gives this redwing credit for 

 eating large numbers of alfalfa weevils in Utah. "Of 42 birds ex- 

 amined, only 2 had failed to eat at least a trace of the weevil, and it 

 was taken on an average of 5.24 adults and 27.16 larvae per bird. In 

 bulk it amounted to 40.76 percent of the stomach contents." 



George F. Knowlton (1944) says that a redwing, probably of this 

 race, "was collected in an alfalfa field southeast of St. George, Utah. 

 Microscopic examination of its stomach contents revealed that it 

 contained a great mass of pea aphids (Macrosiphum pisi) estimated 

 to exceed 1,400 individuals. The pea aphid population in this field 

 was high enough to cause moderate crop injury. A second male 

 red-wing was collected approximately one-half mile away along an 

 alfalfa-field fence line and near to sugar-beets. This stomach con- 

 tained 85 pea aphids; one of four additional aphids it contained was 

 a green peach aphid (Myzus persicae), a species that causes some 

 damage to nearby sugar-beets intended for seed production." 



