What mankind has done so far only led to extinction of hundreds of species of animals and uncountable number of species of insects, cutting enormous amount of forests and poluting the world.
And the argument that animals would've died altogether if we wouldn't kill some of them is one of the most ridiculous things I've heard in my life.
As Chris mentioned, animals existed millions of years ago, unlike humans. And they didn't die out because we didn't kill them. Those who were too weak to find food did, others evolved.
There are still, however, virgin places where people don't live or are not allowed to kill animals or effect them in any other way. Say, you get a $100 fine if Galapagos islands customs guys find a banana in your bag on your way there or a single stone on your way back, you are not allowed to go anywhere without your guide, you are not allowed to make any noise. Guess what? Animals are quite happy there on their own. Much happier than the ones that you believe you are "saving".[DOUBLEPOST=1394000717][/DOUBLEPOST]oops. I didn't notice the last post by Hultsy. Sorry/.