Men from Dinka tribe stand amongst cows in a Dinka cattle herders camp near Rumbek

Men from Dinka tribe stand amongst cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. Picture taken December 14, 2013. (Goran Tomasevic/Reuters)

Men from Dinka tribe stand amongst cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. Picture taken December 14, 2013. (Goran Tomasevic/Reuters)