THE DISTRIBUTION OF BIRD LIFE IN THE 

 URUBAMBA VALLEY OF PERU. 



A:REP0RT on the birds collected by the YALE UNIVERSITY-NATIONAL 

 GEOGRAPHIC SOCIETY'S EXPEDITIONS. 



By Frank M. Chapman 



Of the American Museum of Natural History. 



INTRODUCTION. 



The work of the Yale University-National Geographic Society's 

 Expeditions in the Urubamba region of Peru, under the direction of 

 Prof. Hiram Bingham, has included not only the archaeological inves- 

 tigations which have made the country explored so widely known, 

 but also researches in other branches of science, the whole being 

 designed to form a comprehensive survey of the physical conditions 

 and biological resources of the area under consideration. 



The task of making collections in vertebrate zoology was entrusted 

 to the well-kno^vn naturalist, Edmund Heller, formerly of the Bio- 

 logical Survey, and the representative of the United States National 

 Museum on the Roosevelt Expedition to British East Africa. The 

 fact should be emphasized that Mr. Heller's first object in the field 

 was the collection of mammals, and every one faniiliar with the diffi- 

 culties of mammal collecting in the Andes will appreciate the skill 

 and energy he displayed in amassing a collection of no less than 884 

 specimens.^ 



In collecting birds I^ir. Heller attempted to secure species rather 

 than specimens and his collection, therefore, contains a much larger 

 number of forms than its size would lead one to expect. 



Mr. Heller was in the field from April to November, 1915, during 

 which time he made collections from the upper limit of life above the 

 La Ray a Pass (altitude 14,200 feet) to the dense forests of the humid 

 Tropical Zone in the Rio Comberciato (altitude 1 ,800 feet). Between 

 these extremes he worked at intermediate points representing every 

 life zone in both its humid and arid aspects. Heller's work in the 

 forests of the humid Temperate Zone at tmiber line (approxim^ate 



1 A report on this collection by Oldfield Tliomas has been published in the Proc. U. S. Nat. Mus., 

 vol. 58, pp. 217-249. 



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