ARUSHA, Tanzania — Roger Gower, an experienced British helicopter pilot, was flying low over a wildlife reserve near the Serengeti National Park in Tanzania on Friday, searching for signs of poaching, when he spotted an elephant carcass. He circled back for a closer look.

Then gunshots rang out from below. Apparently he had happened on the carcass just after the elephant had been killed, and the poachers were still on the scene.

A bullet punctured the underside of the helicopter and sliced through Mr. Gower’s leg and shoulder. He managed to crash-land the helicopter, but died of his injuries soon afterward.

“It’s tragic, what happened, but this is the reality of what’s going on,” said Frank Pope, the chief operations officer for Save the Elephants, a prominent wildlife organization in neighboring Kenya. “You’ve got desperate people who are armed and committing a crime. When you’re doing antipoaching operations, you’re on the sharp end.”