also has a hospital, although the medical supply is very much dependent upon the prevailing political situation. The vast majority of the population is Teda, one of the two ethnicities of the Toubou people. However, some clans are Daza, the other Toubou ethnicity, who left their traditional homes in the lowlands to the south and moved north to the Tibesti. The Toubou live primarily in northern Chad, but also in southern Libya and eastern Niger. The Toubou language has two main dialects, Tedaga, spoken by the Teda, and Dazaga, spoken by the Daza. Despite their differences, the two Toubou groups generally identify as a single ethnic group. The Toubou elect a chief, the Derdé, from the Tomagra clan, although never from the same family consecutively. Historically, individual clans rarely had more than a thousand members and were quite dispersed throughout the Tibesti. the population of the Tibesti was officially estimated at 21,000 inhabitants. that number has risen to 54,000 inhabitants. Yet the Toubou, in general, are semi-nomadic, moving between the mountains and other regions, and thus the Tibesti may have no more than 10,000 to 15,000 permanent residents. Traditional Toubou life is punctuated by the seasons, divided between animal husbandry and agriculture. Twentieth-century anthropological studies show Toubou, particularly around palm groves, living in primitive round huts built with stone walls bound by mortar or clay, or built from clay or salt blocks. In the highlands, the buildings were built of stone, forming circles in diameter and high, which served as shelters for goats, or as granaries, or as human shelters and defense structures. In other cases, the Toubou lived in tents that could be easily moved between the fields and the palm groves. History Human settlement There is evidence of human occupation of the Tibesti dating back to the Stone Age, when denser paleovegetation facilitated human habitation. The Toubou were settled in the region by the 5th century BC and eventually established trade relations with the Carthaginian civilization. Around this time, Herodotus mentioned the Toubou, whom he labeled "Aethiopians", and described them as having a language akin to the "cry of bats". Herodotus further remarked on a conflict between the Toubou and the civilization of Garamantes based in present-day Libya. Between AD 83 and 92, a Roman traveler, likely a trader, named Julius Maternus, explored the territory of the Tibesti Mountains with, or under the charge of, the king of