Vol.X 

 iS93 



Allen, Origin and Distribution of N. A. Birds. IOQ 



We have now passed rapidly in review the Swimmers, Waders, 

 and Shore-birds, with the following resnlts : Total number of 

 genera, 93 ; of which 74, or So per cent., are either cosmopolitan, 

 tropicopolitan, circumpolar, or subcircumpolar, leaving 19, or 20 

 per cent., as American, of which only 11, or about 12 per cent., 

 are distinctively North American ; one half of these belong to the 

 single family ScolopacidaB. 



The North American Gallinae number 12 genera, of which 

 one, Ortalis, is tropical, while Meleagris is partly so. The 

 remaining ten genera fall into the two subfamilies, PerdicinaB and 

 Tetraoninae. The four genera of the former are exclusively 

 American ; none reach the cold temperate zone, and all range to 

 the southward of the United States ; three of them are also exclu- 

 sively western. Their metropolis is Mexico, where all occur, 

 and where they have their greatest numerical representation. 

 They have no representatives in South America, and no near 

 relatives in any part of the Old World. 



The Tetraoninse are as emphatically northern as the Perdicinas 

 are southern. Of the six North American genera, three are 

 circumboreal, one ( Tympanuchus) is practically eastern, though 

 formerly, in Post-Pliocene times, according to Dr. Shufeldt, 

 ranging to Oregon ; the remaining two, Pcdioccetes and Centro- 

 cercus, are western. 



Of the eight genera of Pigeons, one, Cohimba, is subcosmo- 

 politan ; two, Ectopistes and Zenaidura, are North American, 

 though the breeding range of the latter extends to the tropics; the 

 remaining five are tropical American, of which four barelv cross 

 our southern border. The Columbine element in our fauna is 

 thus obviously of tropical American origin. 



Of the Birds of Prey, the three genera of Vultures are of course 

 tropical American in origin, and still largely so in distribution, 

 reaching only the warmer parts of North America. Of the six- 

 teen genera of the FalconidaB, nine are either circumboreal or 

 subcosmopolitan, and these all date back, with about the same 

 distribution as now, to the Miocene, while some are known from 

 the Eocene. The remaining seven genera must be ranked as tropi- 

 cal, five of them extending but a short distance into the United 

 States. Hence not a single genus of this large family can be 

 classified as distinctively North American. The same remarks 

 are nearly true of the Owls, four of the twelve genera being cir- 



