Pour le sport

"Come to think of it," he said, "I have the same inadequacies with everybody. I'm just a boy of good family. You say I am bright, but that's about all. Really, I've never done anything of interest." This from someone who had spent a summer as an overseer on a rubber plantation in Africa, and during another vacation had hunted tigers in India, pour le sport. (by Andrew Salter)

Hello,

What does "pour le sport" mean?

Thanks!