476 



ESSENTIALS OF ZOOLOGY 



species of field mice. This zone is found in the Rockies as far south 

 as southern New Mexico. There is some evidence of Canadian fauna 

 in the Chisos Mountains of Texas. 



4. The transition zone (7,000-8,000 feet) is found in the same 

 regions as the above zones. It is also found in the Davis and Chisos 

 and Guadalupe Mountains of Texas. It is covered with pine trees 



Fig-. 206. — Map of the vertical life zones of Texas and adjacent areas. (Aftej- 



Bailey. ) 



(mainly Pinus ponderosa). Abert's squirrel is found in the Transi- 

 tion zone as is one species of horned lizard. 



5. The Upper Sonoran zone (6,000-7,000 feet) is the pifion belt 

 distinguished by the nut or pifion pine and cedars. The zone extends 

 from western Texas through New Mexico, Colorado, Arizona, and 

 into southern California. Characteristic animals are the piiion jay 

 bird, and the large rock squirrel. 



