THE ORIZABA GROUP 



A Study of the Influence of Altitude on the Disthibution of Life 



FROM the dense tropical forests, at the base of Mount Orizaba in 

 Vera Cruz, one may look upward toward the equallj' grand 

 forests of pines and spruces which, 10,000 feet higher, cover the 

 sides of the mountain. 



In the luxuriant vegetation about one are Parrots, Toucans, Trogons, 

 Motmots, and many other tropical birds ; and from their home one may 

 see the zone where Crossbills, Evening Grosbeaks, Juncos, Brown 

 Creepers, and other boreal birds are nesting. Owdng to differences in 

 altitude, which are the equivalent of differences in latitude, the three 

 great Life Zones which go to make up the faunal regions of North 

 America are thus represented in this one group, which may be said to 

 epitomize all the other groups contained in this hall. 



The studies for this view of Mount Orizaba were made at Cordova 

 (altitude 3,500 feet), at the upper border of the Tropical Zone. The 

 primeval tropical forest having long since been cut off in this region, it 

 was necessary to descend to a level of about 1,000 feet, near Motzor- 

 ongo, to secure studies for the forest depicted. The accompanying 

 view of the Rio Blanca was also made near this point, from which Mount 

 Orizaba may be seen in the same relation in which it is here painted. 



The birds contained in this group are representative species of the 

 tropical portions of the State of Vera Cruz. They have been selected 

 to show the tropical character of the bird-life of this region, rather than 

 the bird-life of any particular part of it ; and represent but a small part 

 of the avifauna of several hundred species. 



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