In the south, traversed by the Niger and Senegal rivers, are fertile areas where cotton, rice, and peanuts are grown. Elsewhere the country is arid desert or semidesert and barely supports grazing (mainly cattle, sheep, and goats). The Niger serves as an important transportation artery and a source of fish. The main ethnic groups are the Mande (Bambara, Malinke, and Soninke), who are chiefly farmers and fishermen, and the Fulani and Tuareg, who are pastoralists. About 90% of the population is Muslim; most of the remainder follow traditional religions. While French is the official language, Bambara is spoken by 80% of the population and there are many other African tongues.