Jon Dunn/FIELD NOTES

The Carpodacus Finches

The Western Tanager, June 1976

Carpodacus-Finches-illustration-by-mary-ellen-pereya 

Illustration by Mary Ellen Pereya

The three species of Carpodacus finches—the Cassin's the Purple, and the House Finch—have caused numerous problems in field identification. While the species generally occupy their own separate niches, they overlap enough to cause considerable confusion, particularly during the winter. Van Remsen has written an excellent article on the identification of the Cassin's and Purple Finch (Colorado Field Ornithologist, No. 25) and much of the material that follows was drawn from that source.

By far the most widespread of the three finches is the ubiquitous House Finch, occurring everywhere in Southern California except the dense montane forests. The male's face and head are a fairly bright reddish color (sometimes orange or yellow), with conspicuous streaking throughout the underparts. The female is a plain brownish color with uniform streaking underneath. Both sexes have a square-cut or slightly rounded tail.

The Purple Finch is considerably less numerous than the House Finch, but the species is fairly common during the breeding season on the coastal slope of the mountains. In the northern part of our region the birds may even be found nesting close to sea level—in very moist coastal canyons. During winter their occurrence is irregular: some winters they are common in the lowlands, and in others they are almost absent. The Purple Finch has a larger, thicker bill than the House Finch, and it also has a distinctly notched tail (as does the Cassin's). The female is a darker, more contrasty bird than the female House Finch, with a very dark brown ear patch, bordered by a pale superciliary. The streaking underneath is also much heavier and darker than on the House Finch, and the pale whitish belly contrasts sharply with the flank streaking. The male Purple Finch has an overall more extensive and richer burgundy color, and it lacks prominent streaking on the underparts (though there may be faint streaking along the flanks). Both the Cassin's and the Purple Finch fly in a more undulating manner (like a goldfinch), while the House Finch has a more direct flight. The flight note of the Purple Finch, a Redwing-like pit, is very unlike the notes of the House Finch. When perched, the Purple Finch frequently gives a musical chu-will-ee note that is more patterned than the random notes of the House Finch. The song is also louder and richer than that of the latter species.

The Cassin's Finch is restricted to the high mountains in Southern California (south through the San Jacintos to Santa Rosa Mt.). Occasionally during the winter the birds descend along the desert slopes, but they are almost accidental on the coast, and I suspect that nearly every report from the coastal lowlands is in error. The diagnostic mark that separates this species from the very similar Purple Finch is the streaked rather than plain undertail coverts (more prominent on the female). The bill of the Cassin's, while having the bulk of that of the Purple, is longer, giving it more of a siskin-like appearance. The underparts of the female Cassin's are more finely and faintly streaked, and while there is usually some indication of an ear patch, it is usually much less distinct than that of the Purple. The upperparts of the female Cassin's are of a paler grayish-brown hue (chocolate brown on the female Purple), with more distinct streaking on the back. The male Cassin's is more of a rosy-red color, and the shading is much less extensive than on the Purple Finch, giving the underparts a much paler appearance. The color is essentially confined to the cap, setting off a bright red crown that contrasts sharply with the brown nape. The back is largely a pale grayish brown with Very distinct dark brown stripes, and the rump is a dull grayish-brown. (On the Purple Finch the burgundy hue extends from the crown to the nape, and even through the back and the rump. The back streaking is also much less distinct.) The flight note of the Cassin's., a whistled che-wheet, is very unlike the pit note of the Purple, and the species is less vocal while flying than the Purple, which calls constantly in flight. The song of the Cassin's is also less rich and patterned—more like that of a goldfinch.

Originally Published Western Tanager Vol. 42 No. 9 June 1976


 

Transcribed for the Los Angeles Audubon Society (LAAS) Western Tanager "Articles from the Archives" www.laaudubon.org. July 2013 by SMC.

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