The rapid invasion is a major threat to the environment and rural people’s livelihoods.
Pastoralism is a central part of many Africans' identity. But how and when did this way of life get started on the continent? Ancient DNA can reveal how herding populations spread.
Herders and farmers are unhappy about the way a corrupt state exploits rural peasants.
A big rise in armed attacks in the Sahel - and the intensity of the attacks in recent years - is now seen as a major source of concern.
The idea that terror groups like Boko Haram fund their activities through ivory poaching in Africa is a compelling narrative. But it’s undermining wildlife conservation and human rights.