I am not sure what argument you are referring to, but I think you are referring to appeal to nature. And if it is, I am not not making an appeal to nature fallacy. The AtN Fallacy is that because something is natural means that is good, which well fallacious. I am not making a moral judgment about the rocs attacking people. I am saying that we don't have a reason to mess with it. This is just something that happens, and besides, ecosystems. Killing predators can have a domino effect downwards, but I don 't think this is the time or place to go into that. And if you aren't talking about that argument, be more specific.