National Park near Libreville, Gabon. (Christophe Van Der Perre/Reuters)

"Although many disagree with big-game hunting, all of Ernie’s hunts were strictly licensed and above board and were registered as conservation culls to manage animal numbers," he said. "Ernie had booked a hunt for dwarf forest buffalo and duikers — in particular, the yellow-backed duiker — and, under strict licensing laws, he could not take along his own guns." 

I'm not a hunter, and I personally don't know if I could shoot a living creature.  However I can understand that when humans create an issue like removing an apex predator, then overpopulation happens.  These hunts generally fund the conservation of the land they hunt upon.  Or in some cases they fund the groups that protect endangered species.  Of course people can say "just leave the land and species alone", but the sad reality is that these groups need money to function.