Dear Ronald,
No offence meant. Perhaps I wasn't clear enough, so I'll try again.
The identification of the Lascaux bird as being probably a pidgeon or a dove has absolutely nothing to do with Christianity. It is a purely scientifically made identification based on observation of the type of beak, its comb, and the form of the birds body and head. Accusing the observers of being biased by Christianity is absurd. Of course we know that it eventually also became a Christian symbol, but similarly identifying an eagle in Egyptian art does not mean being biased by the American flag either. The picture of a dove at Lascaux is unique, since all other cave art birds are owls, the later symbol of the goddess Athena.
Now of course we don't know how far in the past the association of Athena and the owl reaches, but it is an interesting point, since Athena is also said to have produced, 'created', the first modern humans together with her husband, while archaeology and modern DNA-analyses places the origin of modern humans some time between 200,000 and 50,000 BC in Africa, while the Greeks too placed the origin of Athena in Africa.
However, if you mean to propose that the cave art at Lascaux may just as well be as old as the time of Jesus or later, just because of the appearance of the dove in one scene, you surely will have to come up with better evidence than just the notion that the dove also happens to be a Christian symbol, especially since the dove as a symbol is know from many cultures thousands of years earlier, and in this case 30,000 years earlier. Unless you can prove that this cave art is not at all that old, fantasizing Christian origins is out of the question.
Anyhow, the motif I was talking about is the bird on a pole and a bird-headed man, regardless of the type of bird. Both motifs are found in predynastic Egyptian tomb paintings. What is more, in Egypt the predynastic bird on the pole or the king's serekh in most cases also does not look like an eagle or hawk at all but indeed looks more like a loveable dove, similar to the picture at Lascaux, while on the other hand the heads of the Egyptian birdmen actually makes one think of owls instead, due to the fact that the eye of the Predynastic Egytian birdman stick-figures seems to occupy his whole head, drawn as a circle with a point in it, which later became the symbol (hieroglyph) of the sun. Whether this too may have evolved into the association of Athena and the Owl, needs further study. If so, it would be further proof that the Greek goddess Athena and the Egyptian goddess Neith - as a wife of Osiris - were indeed once the same goddess, and in turn may even go back to the cave art of southern France as well.
Regards,
Ian