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 252 THE CONDOR Vol. XVI Arkansas Kingbird. Tyrannus verticalis. Say Phoebe. Sayornis sayus. Magpie. Pica pica hurlsonia. Black-headed Jay. Cyanocitta stelleri annectens( ?): Yellow-headed Blackbird. Xanthocephalus xanthocephalus. Red-wing Blackbird. Agelaius phoeniceus, subspecies? Bullock Oriole. Icterus bullocki. Brewer Blackbird. Euphagus cyanocephalus. Pale Goldfinch. Astragalinus tristis pallidus. Western Savannah Sparrow. Passerculus sandwichensis alaudinus. Western Lark Sparrow. Chondestes grammacus strigatus. Western Chipping Sparrow. Spizella passerin a arizonae. Merrill Song Sparrow. Melospiza melodia merrilli. Spurred TOwhee. Pipilo maculatus megalonyx. Lazuli Bunting. Pazserina amoena. Bank Swallow. Riparia riparia. Yellow Warbler. Dendroica aestiva. Western Yellow-throat. Geothlypis trichas occidentalis. Interior Tule Wren. Telmatodytes palustris plesius. Western Robin. Planesticus migratorius propinquus. Mountain Bluebird. Sialia currucoides. As already stated, the area under discussion is about thirty miles long an d ten wide at its lower end, which, because of its triangular shape, gives an area of about 150 square miles. Of this area 62,000 acres are in alfalfa, plow land, and orchards. Various private companies in the past have attempted to water this area, but the final development has been by the Reclamation Ser- vice, whose work, just completed, has extended over the past ten years. As this land came under irrigation the various species of birds adapted to the changed conditions spread out from their former haunts along the Yakima River and took possession of this new territory. A few species-from the pre- vious desert have managed to survive, others have retreated into the yet un- irrigated sage, while others have adapted themselves to the new condition. with a wonderful increase in numbers. The figures which ! give of the actual number of individuals of each spe- cies, are only estimates, and some may be greatly in error; yet they are based largely on four years observation of the species nesting on a definite area under general valley conditions, and are more satisfactory than the rather indefinite adjectives usually used, whose values vary with each observer and each locality. In the list of species already given as representing the probable desert condition, the following changes have occurred. The two species of grouse, the Dusky Horned Lark, Brewer Sparrow and Sage Thrasher, refusing to live separate fro TM their beloved sage brush, have retreated before the irrigation, and none are now found on the tract. The Burrowing Owl has neither sur- rendered his territory nor apparently increased in numbers, but still hangs on tenaciously, digging his burrows in the unirrigated knolls and along the dry roadsides. The Short-eared Owl is more abundant than in the dry land, and like the Burrowing Owl nests on the dry knolls. It is very abundant in the 'al! and winter but the large number is probably made up mostly of immi- grants. Say Phoebe, the Western Vesper Sparrow and the White-rumped Shrike have accepted the new conditions and are more often met with than in