The richest of all regions for birds, this area is home to over one-third of all known species and it contains almost half the world's total birds, including its winter migratory birds. Seventy percent of its land area is low-lying, well watered and tropical. With 40 percent of the South America region covered by savanna and 32 percent by tropical rainforest, there are more than twice as many endemic families in the Neotropical as in any other region