A REVIEW OF THE RACES OF THE SPOTTED 



BABBLING THRUSH, PELLORNEUM 



RUFICEPS SWAINSON 



By H. G. DEIGNAN 

 Associate Curator, Division of Birds, U. S. National Museum 



Having long been dissatisfied with the conventional treatments 

 of the well-known spotted babbling thrush, Pellorneum ruficeps 

 Swainson, I have recently brought together a series of 339 specimens, 

 possibly the greatest aggregation of this species that has ever been 

 studied. The institutions that have cooperated in the project, and to 

 the authorities of which my thanks are hereby rendered, are 



1. Museum of Comparative Zoology, Cambridge, Mass. (M.C.Z.) 



2. American Museum of Natural History, New York, N. Y. 

 (A.M.N.H.) 



3. Academy of Natural Sciences, Philadelphia, Penn, (A.N.S.P.) 



4. United States National Museum, Washington, D. C. 

 (U.S.N.M.) 



5. Museum of Zoology, University of Michigan, Ann Arbor, 

 Mich. (U.M.M.Z.) 



6. Chicago Natural History Museum, Chicago, 111. (C.N.H.M.) 



7. Los Angeles County Museum of History, Science and Art, Los 

 Angeles, Cahf. (L.A.C.M.) 



As might be expected in a terrestrial, sedentary bird of extensive 

 range, considerable geographic variation appears in this material, and 

 much of what has always been treated as simple individual varia- 

 tion proves to be of subspecific importance. Subspeciation is found 

 not only in the major zoogeographic areas where, by analogy with 

 other species, it might be expected to occur, but also within com- 

 paratively small portions of those areas, and trenchantly different 

 forms are often separated from each other by rivers and hill ranges 

 that to most other lowland birds of the Oriental Region would prove 

 no barrier at all. The number of populations that have seemed to 

 me worthy of nomenclatorial recognition will be received with com- 

 plete disbelief, unless the importance of these delimiting geographic 

 factors is realized. Acceptance of it, however, will at once explain 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 107, NO. 14 



