" The Distribution of Bird-Life in Colombia " 



A Review* 



By A J{ T 11 r K* A. A L 1. K N 



Assistant Professor of Oniitliology, Cornell University 



OF tlic niiK'li-'L'ii ur twciitv lliou- 

 saud species and subspecies oi' 

 birds known (o iiiliahii ibe 

 world, from four to live lliousand, or 

 about one fourth, ai-c found in South 

 America. Soutli .Vnici'ica. therel'ore, is 

 the richest part of tlic :Li'lol>t' in variety 

 id" bird life. 'Hie vast stretches of forest 

 and Hanos. the hiuli mountains, tlie iso- 

 hiti'd ri<lp's. the ,i:rcat altiliulcs and ex- 

 tensive latitudes, with their resulting- 

 diverse climatic conditions, all combine 

 to create the inniiniei'ahle isolated en- 

 vironments that ai'e necessary for tbe 

 development of a lii-eat variety of 

 species. 



In South .Vmerica there are found 

 not only a larger numl)er of -species but 

 also a far larger number of families 

 than in other regions of the world, 

 showing either that the birds have 

 diverged more widely from their ances- 

 tral types or that more of the connect- 

 ing links have been preserved. The lat- 

 ter is more likely to be the case because 

 most of the families are still those 

 which are considered low in the scale of 

 evolution. Some of these families have 

 many representatives in Africa ; others 

 seem related to Australian forms, and 

 still others, like the humming birds, 

 tanagers, orioles, and warblers, un- 

 doubtedly represent the stock from 

 which many of our Xorth American 

 liirds were deriv(>d. Indeed, the origin 

 of Xorth American birds and the p(>r- 

 plexing problems of their distribution 

 and migration are so closely linked 

 witli the origin and distribution of 

 South American birds that it seems 

 necessary to nnderstand the ])roblems 

 of South American bird life before we 

 can ofo verv far with our own. When 



we laiow whei'e the ancestors of our 

 birds li\fd and where they probably 

 came from, we can deal more intelli- 

 gently with the mysteries that still en- 

 shroud the li\('s anil iiio\einents of our 

 own birds. 



It was with this ultinuite aim that, 

 in December, 1910, the American Mu- 

 seum of iVatural History inaugurated 

 its extensive zoological survey of South 

 .\nierica. As the first great step in its 

 accomplishment, Dr. Chapman has now 

 j)iiblished the result of seven years' 

 study, "The Distribution of Bird-Life 

 in Colombia." 



When the work was conceived, it was 

 thought that most of the exploration 

 had already been accomplished and 

 that the list of South American birds 

 was reasonably complete. The first 

 contribution was to be in the nature of 

 a survey of the distribution of the birds 

 already described. As material came 

 in from the various collectors, however, 

 and also through expeditions which Dr. 

 Chapman himself led into Colombia, it 

 was discovered that there was still a 

 good deal of j^reliminary work to be 

 done. In fact, before the paper on the 

 distribution of bird life could be pre- 

 pared. Dr. Chapman found it necessary 

 to describe from Colombia alone, 22 

 species and 115 subspecies of birds new 

 to science. 1 



But it was not only in the descrip- 

 tions of new species that inoneer work 

 had to be done. Some of the expedi- 

 tions extended their explorations into 

 little-known parts of Coloml)ia that 

 had never been accurately mapped. 



' BiiUetin Amr'rwan Museum Natural Historii, 

 XXXI. 1912, pp. 139-166; XXXIII. 1914, pp. 

 167-192. pp. 606-637; XXXIV, 1915, pp. 363- 

 388, pp. 63.5-662. 



* BuUitin of the Amiririni M„s,„w <,f Siilinnl Uixlorii: Vol. XXXVI, 1017, The Distriljutioii of Bird- 

 Life in ColomVjia; A Contribution to a Biological Survey of South America, by Frank M. Chniiman. 



4 S.J 



