“I like keeping things alive,” Boubacar Diallo told me. He had raised animals his whole life, a hobby he inherited from his father, a soldier in the Nigerien Army. “Anyone will tell you the address to my house is the place where the cattle are outside.” Diallo climbed a ladder to reach some hay bales on the roof of a ramshackle lean-to under which three goats, their fleeces the color of old snow, were huddled next to a flock of pigeons. He hopped down and tossed the bales into the pen. A few birds followed him.

It was early…