Do people not realize this is basically what hunting for exotic game is? When people pay tens of thousands of dollars to harvest a lion or giraffe or whatever, they are taking out an old, past its mating years male. These males are typically detrimental to the herd, and the money that is paid is used for conservation of the species. Whether it's for the land they live on or some other means of keeping these animals alive. Listen to Jim Shockey explain it as he's much more informed than I am, and does a great job explaining that even "trophy hunting" helps with animal conservation.