. The birds of California : a complete, scientific and popular account of the 580 species and subspecies of birds found in the state. Birds; Birds. The Bell Sparrow in the chamisal associa- tion. Two of these re- cords were made in the pure desert association of the San Fernando Valley, Opuntia bemardina, Yucca whipplei, Sambu- cus glanca, Rhus laurina, and the rest. Both nests were in "broom sage" (A rtemisia dracuncu- loides), as also were two found in eastern San Luis Obispo County, April 15, 1914, although the latter may possibly have marked a heretofore un- recognized extension
. The birds of California : a complete, scientific and popular account of the 580 species and subspecies of birds found in the state. Birds; Birds. The Bell Sparrow in the chamisal associa- tion. Two of these re- cords were made in the pure desert association of the San Fernando Valley, Opuntia bemardina, Yucca whipplei, Sambu- cus glanca, Rhus laurina, and the rest. Both nests were in "broom sage" (A rtemisia dracuncu- loides), as also were two found in eastern San Luis Obispo County, April 15, 1914, although the latter may possibly have marked a heretofore un- recognized extension of A. n. canescens. The remarkable sit- uation as regards A. belli and A. nevadensis invites hypothesis. The undif- â ferentiated members of the original species, Amphispiza preglacialis, pushing northward and westward from a distri- bution center in Sonora, invaded southern Cali- fornia and the Great Basin region. Later, becoming isolated by the Sierro-San ice barrier, the form belli evolved, while its counterpart and erstwhile brother was evicted from California by the refrigeration of the eastern slopes of the Sierras and the White- Mountains-Inyo-Desert system. In the reoccupation of this Owens Valley country a new form, A. n. canescens, has evolved, and this form, pushing its conquest westward, has stormed the Tehachipe and the bound- ing barriers of the Mojave Desert, and has spilled over variously into the Kings-Kern and San Joaquin regions. If this hypothesis be the correct one, we may expect a steady advance on the part of A. n. canescens, and a gradual retirement of the more strongly marked but weaker belli. 280. Photo by L. Huey and D. R. Dickey - BELL SPARROW: ADULT WITH YOUNG. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Dawson, William Leon, 1873-1928; Dickey, Donald R. (Donald Ryder), 1887
Size: 1421px × 1758px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1923
