The Oromo people are one of the most numerous in Africa. Census data are not reliable but there are probably twenty million people whose first language is Oromo and who recognize themselves as Oromo. In the older literature they are often called Galla. Except for a relatively small number of arid land pastoralists who live in Kenya, all homelands lie in Ethiopia, where they probably make up around 40 percent of the total population. Geographically their territories, though they are not always contiguous, extend from the highlands of Ethiopia in the north, to the Ogaden and Somalia in the east, to the Sudan border in the west, and across the Kenyan border to the Tana River in the south.Though different Oromo groups vary considerably in their modes of subsistence and in their local organizations, they share similar cultures and ways of thought.