Does anyone out there have a good bio-ecological definition for 'predator'? I'm trying to figure out what makes a predator specifically that, and why for instance a parasite isn't considered just a rather slow subset of predator. In what inheres predatorness? In pouncing? In killing quickly? In eating whole? In being larger than the prey? I can think of predators that violate each of these conditions.
When we talk about a species (e.g., humans) not having any 'natural predators', that presumes the exclusion of parasites, of which we got plenty. I can't find a good definition of predator to explain this to me. Anyone help me out?