Dawkins' and Singer's arguments require one to believe that there is, ontologically and morally, no difference between taking the life of a fellow sentient creature and taking the life of another human being.

If you had any familiarity with Singer you would know that this is bullshit. He makes quite clear that he considers the taking of a human life more wrong than the taking of, say, a cow's, on the preference-utilitarian grounds that, as a person (a being with a conception of a "self" persisting over time), the human is more able to value his own life than the cow, a non-person, is. In other words, you wrong the human you kill more than the cow you kill. He does believe that it wrong to place human interests, by default, above animal interests of comparable value (say, their interest in avoiding the torment inflicted upon them in the billions by the modern meat industry); but this is quite a different matter from what you allege. Animals unable to consciously value their own lives simply have no interest in staying alive, Singer implies, which is why he has, as Joey Kurtzman of Jewcy says, "left many of us with the understanding that death has no value whatsoever in Singer's utilitarian calculations, and is undesirable only to the extent that it comes with associated suffering. If Charles Eisenstein were to detonate a neutron bomb on a small island full of chocolate labrador puppies, I don't know that Singer would find this of any great concern."

In the future please deign to stay away from straw men.