Animals are survival machines, and it's not necessarily who is strongest who will win, unless you mean "strongest mentally". Either way, humans are shit, yet we're still around? We're not particularly strong, we're not particularly good at anything apart from communication. Yet we are now the dominate species on the world.
EDIT: Either way, I was replying to the quote "It's survival of the strongest", which is wrong. The nearest you could get to an accurate statement would "Surival of the fittest", as long as you mean the most fit for their task or something...