sentences:  As of 2002, there were at least 134 species of mammals and 532 species of birds (354 species of residents and 155 migrants) in Chad.Before the 20th century, Chad reportedly had a rich fauna of large carnivores in the Lake Chad region, but due to deforestation, hunting and competition from livestock most of the population of lions, leopards, rhinoceros, and hippopotamus have disappeared from the region.The Zakouma National Park is an important habitat with the highest number of large mammals.