Habitats selected at a significantly higher rate than at least one other habitat included grasslands by five species (western kingbirds, chipping and lark sparrows, and lark and lazuli buntings), willow riparian by four species (Lucy's warblers, lark and lazuli buntings, and lesser goldfinches), mesquite by four species (ash-throated flycatchers, Lucy's warblers, lark sparrows, and lazuli buntings), cottonwood riparian by three species (Lucy's warblers, lazuli buntings, and lesser goldfinches), oak by two species (chipping sparrows and black-headed grosbeaks), and desert scrub by one species (lazuli buntings).
we included the ash-throated flycatcher (Myiarchus cinerascens), western kingbird (Tyrannus verticalis), warbling vireo (Vireo gilvus), Lucy's warbler (Oreothlypis luciae), western tanager (Piranga ludoviciana), chipping sparrow (Spizella passerina), lark sparrow (Chondestes grammacus), lark bunting (Calamospiza melanocorys), black-headed grosbeak (Pheucticus melanocephalus), lazuli bunting (Passerina amoena), Bullock's oriole (Icterus bullockii), and lesser goldfinch (Carduelis psaltria).
To illustrate the comparative phylogeographic approach, I compared the geography of mtDNA variation in five bird species: the Canada goose (Branta canadensis, Anserinae; Van Wagner and Baker 1990), chipping sparrow (Spizella passerina, Emberizinae; Zink and Dittmann 1993a), song sparrow (Melospiza melodia, Emberizinae; Zink and Dirtmann 1993b), fox sparrow (Passerella iliaca, Emberizinae; Zink 1994), and red-winged blackbird (Agelaius phoeniceus, Icterinae; Ball et al.
Secondly, the depths of the haplotype trees differ by a factor of four ([ILLUSTRATION FOR FIGURE 1 OMITTED], Table 1), with the Canada goose showing the deepest splits, and the chipping sparrow the shallowest.
The song sparrow occupies several microhabitats (Aldrich 1984), whereas the chipping sparrow and red-winged blackbird occur in the same basic habitat throughout their ranges (AOU 1983).
Red-winged blackbird (18) 0.030 10, 11 Chipping sparrow (7) 0.036 12 Song sparrow (34) 0.026 13, 5 Tufted titmouse (2) 0.038 9 Black-crested titmouse (3) 0.050 9
For example, the most divergent chipping sparrow haplotypes are 0.6%, whereas this species differs by 3.6% sequence divergence from its nearest extant relative.
These five species might have been historically codistributed and responded to events idiosyncratically (fox sparrow and Canada goose) or not at all (red-winged blackbird, chipping sparrow, song sparrow), or were simply not historically codistributed.
For example, one might predict lower levels of dispersal for the song sparrow (34 subspecies) than the chipping sparrow (seven subspecies), but such was not the case.
The two subspecies groups of the plain titmouse, two samples of the mountain chickadee, brown-headed cowbird, and the megarhyncha and schistacea groups of the fox sparrow, exhibit extensive mtDNA differentiation between coastal and interior populations, whereas these east-west splits are not evident in the mourning dove, downy woodpecker, song sparrow, and chipping sparrow. Possibly, the minor southwestern differentiation in the red-winged blackbird and northern flicker is coincident with this general pattern.