. The distribution of bird-life in Colombia; a contribution to a biological survey of South America . ountain in the tropicswithout at once realizing that temperature, as it is influenced by altitude,is obviously the dominant factor in producing the floras and faunas en-countered between base and summit. Where humidity, and in certaininstances, character of the soil, add their influence, the boundary linesbetween life zones are often very sharply defined. One may pass, forexample, from the upper border of the arid tropics on the eastern slope ofthe Western Andes at San Antonio into the dense f
. The distribution of bird-life in Colombia; a contribution to a biological survey of South America . ountain in the tropicswithout at once realizing that temperature, as it is influenced by altitude,is obviously the dominant factor in producing the floras and faunas en-countered between base and summit. Where humidity, and in certaininstances, character of the soil, add their influence, the boundary linesbetween life zones are often very sharply defined. One may pass, forexample, from the upper border of the arid tropics on the eastern slope ofthe Western Andes at San Antonio into the dense forests of the humidsubtropics on their crest in less than two minutes, and experience a completechange in bird-life. But even where temperature alone is active, and thereis no marked difference in rainfall, the forest being continuous, an alti-tudinal difference of 1000 feet may bring one into an essentially new avi-fauna. Such a phenomenon we observed when traveling from El Piiion(alt. 9600 ft.) to just above El Roble (alt. 8600 ft.), on the trail between Bull. A. M. N. H. Vol. XXXVI, Plate XXVI. Faunas Faunas ^^ Colombian-Pacific Subtropical/ gg| West Andean I I Cauca-Magdalena ^ Zone I^ ^^ East Andean I I Caribbean Temperate WKM Zone and Fauna ^^M Orinocan Paramo ^^| Zone and Fauna A- I Amazonian LIFE ZONES AND FAUNAS IN COLOMBIA The dotted area is the arid portion of this Fauna. Tropical Zone 1917.] Chapman, Distribution of Bird-life in Colombia. 85 Bogota and Fusugasuga. The first-named locality has a highly developedTemperate Zone life; while at the second, the fauna of the Subtropical Zoneis equally well represented. A study of the bird-life of the Colombian Andes, shows, therefore, thatit is distributed in four zones, and since the lower zone lies wholly within thetropics it follows that the remaining zones are all altitudinal. While Ihave been tempted to use names for them which seemed especially descrip-tive locally, it has been deemed far more desirable to accept exi
Size: 1326px × 1883px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidcu319240, booksubjectbirds
