 The southern, or Sudanic, zone consists of broad grasslands or prairies suitable for grazing.As of 2002, there were at least 134 species of mammals, 509 species of birds (354 species of residents and 155 migrants), and over 1,600 species of plants throughout the country.Elephants, lions, buffalo, hippopotamuses, rhinoceroses, giraffes, antelopes, leopards, cheetahs, hyenas, and many species of snakes are found here, although most large carnivore populations have been drastically reduced since the early 20th century.