ECOLOGY AND WILD LIFE CONSERVATION 



477 



is the typical upland game bird. Although the passenger pigeon has 

 become extinct, its relative the mourning dove has remained fairly com- 

 mon due perhaps to its habit of nesting almost every month of the year. 

 Amphibia, particularly the salamanders, reach their climax in the south- 

 ern Alleghenv Mountains. Glacial lakes filled with fish are common in 

 the northern half of the biome. 



Southern Evergreen Biome. From coastal Virginia around the Gulf 

 Coast to eastern Texas grow long-leaved pine mingled with such broad- 

 leaved evergreens as magnolia, live oaks, and many evergreen shrubs. 



Lovell 



Fig. 30.2. The "elk line" in an aspen grove in the Rocky Mountain National Park. 

 These aspens are in danger of dying because too much of their bark has been eaten by 

 elk during the winter. Such overpopulation is due to the absence of large predators, 

 such as mountain lions, which normally keep the elk in balance with the available food 



supply. 



The cabbage palm and scrub palmettos give the area a subtropical ap- 

 pearance. Along the coast the trees are festooned with Spanish moss, 

 a gray moss-like plant belonging to the pineapple family. The pine 

 lands are maintained by burning and probably represent only a sub- 

 climax. The largest animal is the alligator. The eastern diamond- 

 back rattlesnake and the cotton-mouth water moccasin abound along 

 with the beautiful coral snake. Lizards and turtles also are common 

 throughout the region. Sea birds nest along the coastal islands of the 



