I have to agree with you to some extent, Maahey, but the behaviour of a mother bird in trying to distract a predator from her nest can be easily explained as instinct. The motive the sociobiologists would ascribe (and they may be correct for all I know) is that she is ensuring that her genes are passed on to posterity. In other words, protecting the nest and fledglings is part of the drive to survive for you and your offspring to the betterment of the entire species. If you don't try to protect them then you are a "weak link" in the species and you and your line "deserve" to fail. Simplistic Darwinism, perhaps? Dunno.
We know that such behaviour has to be instinctive because it seems virtually impossible that a mother bird could pass such things on to her young conceptually unless the situation occurred often enough for the action to be imprinted on the young birds' brains. In that case, logic tells us that only young birds which came from a nest which had been attacked and defended successfully more than once would be likely to survive to pass their genes on except by the merest happenstance.
None of which has any explanatory power in terms of a cat trying to feed a dead dog.
