If a human being identifies as a non-human animal (say a deer or a cow, ad arguendo) and that identification is recognized as valid and legally protected, would that mean people would have the right to kill and eat them?
What happens in a first contact event with fully sentient beings?
In most jurisdictions I am aware of, killing and eating them does seem to be a legal option. In California the statute for murder explicitly applies to human beings, per Penal Code Section 187(a). Mind you there are also protected animal species, hence why I said they claim to be a deer or a cow and not something like a migratory bird that would entitle them to legal protections.
