96 



THE CONDOR 



Vol. XX 



more recent than that of the Subtropical 

 zone; that the Paramo zone reaches sea lev- 

 el still farther south and that its life is de- 

 rived by latitudinal extension and is more 

 recent than that of the Temperate zone; 

 and that the present trend of the distribu- 

 tion of life upon the continent is north- 

 ward, few boreal species having entered Co- 

 lombia in recent geologic times. In other 

 words, the hypothesis advanced is that the 

 enormous mountain ranges forming so large 

 a part of the Colombian region arose as a 

 gradually increasing elevation forced up- 

 wards from a tropical base, the lofty sum- 

 mits with their necessarily cooler climate 

 being populated by the latitudinal extension 

 of the range of species from regions to the 

 northward and to the southward having 

 similar climates, and also by "altitudinal ex- 

 tension as the pressure of life from immedi- 

 ately contiguous regions below forced spe- 

 cies upward, the more adaptable of which 

 survived". 



Three of the four zones are divided into 

 faunal areas. In the Tropical zone five are 

 recognized, as follows: Colombian-Pacific, 

 Cauca-Magdalena, Caribbean, Orinocan, Am- 

 azonian. In the subtropical zone there are 

 two, West Andean and East Andean. The 

 Temperate zone has strongly marked humid 

 and arid divisions but does not appear to be 

 otherwise divided. The Paramo is uniform 

 in character. 



Each of these zonal and faunal divisions 

 is treated in detail, the points made being 

 illustrated with a wealth of half-tones, maps, 

 and diagrams, and tables of bird species. 

 Not the least interesting and instructive of 

 these graphic features are the maps illus- 

 trating the ranges of representative species. 



Part one (pp. 3-169) is devoted to this de- 

 scriptive and philosophic matter. Part two, 

 with some introductory and explanatory 

 matter, largely relative to classification and 

 nomenclature, contains the systematic list 

 of the species concerned. For the most part 

 the comments on each are extremely brief, 

 frequently a mere statement of localities, 

 but even so, the 1285 species and subspe- 

 cies included necessarily make a rather 

 bulky volume. 



The whole report is one of intense inter- 

 est, and the facts and theories concerned are 

 presented in a most attractive and convinc- 

 ing manner. The volume fairly teems with 

 suggestions of problems to be followed up, 

 in addition to the many ingenious and satis- 

 factory explanations advanced for condi- 

 tions as encountered. While naturally much 



of this does not touch directly upon work 

 in North America, still one comes across oc- 

 casional statements of fact or opinion that 

 have a bearing upon our own studies as well 

 as generalizations that are applicable every- 

 where in faunal research. 



It is interesting to note that, quite differ- 

 ent from conditions in North America, no 

 evidence of altitudinal migration in any 

 species was obtained in this country of 

 strongly contrasting mountains and valleys. 

 The explanation of this is doubtless to be 

 found in the equable climatic conditions of 

 each zone the year through. It is not so 

 easy, however, to find an explanation of the 

 fact that the many North American species 

 encountered here in their winter home, pay 

 absolutely no attention to faunal or zonal 

 boundaries. This is decidedly at variance 

 with conditions along the Pacific Coast of 

 the United States, where the ranges of win- 

 ter visitants from Alaska and northwestern 

 Canada are strongly influenced by local cli- 

 matic conditions. 



Of the many North American birds win- 

 tering in or passing through Colombia near- 

 ly all are eastern species. The Western 

 Wood Pewee (Myiochanes richarclsoni) is 

 mentioned as the only bird of the western 

 United States, but the systematic list of spe- 

 cies also includes Ghordeiles acutipennis 

 texensis and Myiodynastes luteiventris, both 

 of which occur in that region, whether or not 

 the Colombian migrants individually hail 

 from within our boundaries. It seems curi : 

 ous to read of a subspecies of our familiar 

 Black Phoebe as "an inhabitant of the Trop- 

 ical Zone but working up the streams to the 

 lower border of the Subtropics", for one 

 would expect it rather amid temperate zone 

 surroundings. 



Dr. Chapman has much to say regarding 

 classification and nomenclature, as well as 

 the treatment of genera and subspecies, and 

 what he says is clearly and vigorously ex- 

 pressed and worthy of careful consideration. 

 In his strong advocacy of personal field 

 work in a study of this sort he assumes a 

 position that will certainly not be combated 

 by any active western ornithologist. In fact 

 it is a little difficult at this day to realize 

 the need of argument to uphold such a self- 

 evident proposition. 



It is but a thankless task to pick out min- 

 or errors in a work of such high general 

 standard, and really the volume under dis- 

 cussion forms a most unprofitable field for 

 such search. As an example of how errors 

 creep in despite most careful proof reading, 



