© Ami Vitale / Panos Pictures..Even in the pre-dawn light, cries of the farmers in the village of Bounessa in the Affole region of Mauritania ring across the valley, challenging the birds that want a share of the ripening sorghum. Bounessa is a village of only 61 families, all of one sub-clan and tribe, the Swaqer of the Hel Sidi Mahmoud. The families were once nomadic, but since they built a dam in 1960, they are settled now. "We were tired going from one place to another. Before the dam (was built) we cultivated where we could. With the dam and the cereals we have a new life. We can buy goats and sheep. Now I have stayed in a permanent house for seven years. "