The Betsimisaraka, the second largest ethnic group, is the most numerous group pursuing trading, seafaring, fishing, and cultivation.The Southwest is defined by the Ivakoany Massif to the east and by the Isala Roiniforme Massif to the north and includes the Mahafaly Plateau and the desert region.The fertility rate is 5.76 children born per woman.
Historically, the largest ethnic group is the Merina located on the high plateau.The High Plateau (Central Highlands) contains a wide range of topographies: round eroded hills, granite outcroppings, extinct volcanoes, and alluvial plains and marshes.It is defined by an escarpment along the east coast and a more gradual slope along the west coast.The arid southwest is inhabited by Antandroy and Mahafaly who pursue cattle raising and limited cultivation.The northern end of the island features the Tsaratanana Massif with an elevation of 9,500 feet. The Antankarana inhabiting this region are involved in cattle raising and tropical horticulture.
Over 18 ethnic groups live on the island including: Merina 26.1 percent; Betsimisaraka 14.9 percent; Betsileo 12.0 percent; Tsimihety 7.2 percent; Sakalava 5.8 percent; Antandroy 5.3 percent; Antaisaka 5.0 percent; Tanala 3.8 percent; Antaimoro 3.4 percent; Bara 3.3 percent; Sihanaka 2.4 percent; Antanosy 2.3 percent; and Mahafaly, Antaifasy, Makoa, Bezanozano, Antakarana, Antambahoaka (less than 2 percent each). The official language of Madagascar is Standard Malagasy (Malagasy Official).