The state holds populations of white-tailed deer, mule deer, antelope, coyotes, mountain lions, bobcats, elk, and birds such as quail, doves, cardinals, bald eagles, red-tailed hawks, and pheasants. In prairie ecosystems, American bison, greater prairie chickens, badgers, and armadillo are common, and some of the nation's largest prairie dog towns inhabit shortgrass prairie in the state's panhandle. The Cross Timbers, a region transitioning from prairie to woodlands in Central Oklahoma, harbors 351 vertebrate species. The Ouachita Mountains are home to black bear, red fox, grey fox, and river otter populations, which coexist with a total of 328 vertebrate species in southeastern Oklahoma. Also, in southeastern Oklahoma lives the American alligator.