Il6 Allen, Origin and Distribution of N. A. Birds. [April 



A large part of the distinctively American element in the 

 North American avifauna seems almost obviously of tropical 

 American origin; for example our Vultures, several genera of our 

 Hawks and Owls, our Cuckoos, most of our Woodpeckers, our 

 Nighthawks, Whippoorwills, Swifts, and all of our Humming- 

 birds ; all of our Flycatchers, Orioles and Blackbirds, and our 

 Vireos and Tanagers ; many of our Sparrows and Grosbeaks ; all of 

 our Gnatcatchers, and the Mockingbirds, some of our Wrens, 

 and a few of pur more southern genera of Warblers, as the 

 Yellowthroats and Redstarts. 



It seems probable that another portion originated in Mexico, 

 mainly on the great Mexican Plateau, as the Quails, the Turkeys, 

 and some of our Pigeons; a number of our Woodpeckers ; the 

 greater part of our Jays, the Pipilos, the various species of 

 Peuccea, Amphispiza and Passer ina ; the Titmice of the genera 

 Psaltriparus, Auriparus, and Chamcea ; our Wrens of the 

 genera Catherpcs and Salplnctes ; the Solitaire, most of the 

 Thrashers, and the Bluebirds. 



Doubtless we may properly recognize as autochthonous or 

 indigenous a half dozen genera of Sandpipers, our Prairie, 

 Sharp-tailed and Sage Grouse, our Woodpeckers of the genera 

 Ceophlceus, Xenoplcus and Sphyraplcus ; the Jays of the 

 genera Cyanocephalus and Cyanocitta and probably Aphelo- 

 coma ; the genera Scolecophagus, Xanthocephaliis, and Doli- 

 chonyx among the Icteridse, and among our Sparrows such 

 genera and subgenera as Passerella, Passcrcnlus, Ammod 'ramus, 

 Spizella, Zonotrichia, Mclospiza, Pooccetes, Spiza, and 

 Calamospiza ; of the Warblers the genera M)iiotilta, Protono- 

 taria, Helinaia, Hclmithcrns, Helminthoplilla, Sylvan ia . 

 and Seiurus, and many of the species of Dendroica ; also Galeo- 

 scoptes, Oroscoples, Hesperocichla, and Hyloclchla. 



As modifications of Old World or circumpolar stock may be 

 mentioned Camptolaimus, Lophodytes, and Chen among Ducks 

 and Geese, and Picicorvns, Rhynchophancs, Hesperiphona, and 

 Leucosticte among Passeres, with of course the hundred or 

 more species and subspecies which belong to circumpolar genera. 



Probably three fourths of the distinctively North American 

 genera and species have reached their present habitats by way of 

 Mexico, and perhaps one fourth or less by way of the West 

 Indies. Many of the local genera and species, as those restricted 



