. 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 Song Sparrows. Taken in Seattle north of us—viz., morph- na, whose range ex- tends from the Columbia River to southernmost Alaska; and rufina, which occupies the southeastern coastal strip of Alaska north to Cross Sound—intergrade so perfectly that some authorities, Grinnell, for example, decline to sepa- rate them at all. But the final test of differ- ence may prove to be other than somatic. The degree of participation in migration may help to
. 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 Song Sparrows. Taken in Seattle north of us—viz., morph- na, whose range ex- tends from the Columbia River to southernmost Alaska; and rufina, which occupies the southeastern coastal strip of Alaska north to Cross Sound—intergrade so perfectly that some authorities, Grinnell, for example, decline to sepa- rate them at all. But the final test of differ- ence may prove to be other than somatic. The degree of participation in migration may help to determine the difference between hypothetical morphna and rufina. All we know so far is that the Song Sparrows of western Washington, morphna, are partially sedentary, perhaps wholly so in the south- ern portion of their range; whereas rufina forsakes the northern portions of its range,— the Cross Sound and Sitka districts—out- right. The probabilities are that the migratory movement of morphna- rufina is, therefore, high- ly composite, that the southern extreme is stable, while the northern end is forced down by a telescoping motion which projects now one element and now another of the composite mass into northern California. The variable character of the material taken in winter in California supports this hypothesis, while 340 Photo by the A uthor "A BIRD OF MODEST MIEN". 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), 1887-1932; Pierce, Wright M; Finley, William L. (William Lovell), 1876-1953; Brooks, Allan, 1869-1946. San Diego ; Los Angeles ; San Francisco : South Moulton Company
Size: 1299px × 1924px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1923
