1914 



RIRDS OF ARIZONA 



91 



1. Colinus ridgwayi 



2. Callipepla squamata 



3. Lophortyx gambeli 



4. Chaemepelia p. pallescens 



5. Scardafella inca. 



6. Parabuteo u. harrisi 



7. Falco fusco-caerulescens 



8. Polyborus cheriway 



9. Otus a. gilmani 



10. Speotyto c. hypogaea 



11. Glaucidium phaloenoides 



12. Micropallas whitneyi 



13. Geococcyx calif ornianus 



14. Dryobates s. cactophilus 



15. Centurus uropygialis 



16. Colaptes c. mearnsi 



17. Calypte costae 



18. Sayornis sayus 



19. Pyrocephalus r. mexicanus 



The Lower Sonoran zone occupies a larger portion of the state than any- 

 other of the faunal subdivisions. It includes the vast desert area of western Ari- 

 zona, and extends as long, narrow ribbons far up the valleys of the Gila River 

 and its tributaries, and along the Colorado River to, and including, the desert 

 of the Little Colorado River, in the northeastern corner of the state. In these 

 Lower Sonoran valleys of Arizona many of the distinctive southwestern desert 

 types attain their greatest development. The group of thrashers is a good ex- 

 ample of this class ; while there are distinctive low zone species of doves, quails, 

 and woodpeckers, several species of each, with great abundance of individuals. 



The various associations found within the Lower Sonoran zone present com- 

 binations of species quite as distinctive as those inhabiting different zones. 

 Among these may be mentioned the association of the mesquite-bordered streams, 

 in which are found the White-winged Dove. Vermilion Flycatcher, Crissal 

 Thrasher, Lucy Warbler, Sonoran Yellow Warbler and Verdin ; that of the giant 

 cactus, with the Sahuaro Screech Owl, Elf Owl, Gilded Flicker, and Arizona 

 Crested Flycatcher ; and that of the creosote and cholla cactus covered mesa, 

 with the Black-throated Sparrow, Palmer, Bendire and Leconte thrashers, Cactus 

 Wren, Plumbeous Gnatcatcher and Texas Nighthawk. These lists, of course, 

 are not at all complete, but include merely some of the most conspicuous and 

 typical birds of each association. The subject is deserving of careful study, 

 such as cannot be attempted in this connection, and should include consideration 

 of the mammals and reptiles of the regions as well as of the birds. Many of the 

 correlations noted even in a cursory survey of the available data, are extremely 

 interesting. 



Species Occurring in the L<pper Sonoran Zone 

 summer visitant 



1. Cynanthus latirostris 4. 



2. . Myiarchus 1. olivascens 5. 



3. Myiocbanes r. richardsoni 6. 



Icterus pansorum 

 Vireosylva g. swainsoni 

 Vireo vicininr 



