The guide would answer, in lowered tones, "Monsieur, ze chamois are two a penny and tout le monde shoots them. But have you ever heard of anyone who has shot a dahu?"
"Gad, no. What's a dahu?" his interlocutor would ask.
The guide would then tell him of the dahu, variously described as looking like a deer or fox, and out they would go looking for it, but never finding it. The chamois (or gems, as it is sometimes called) was quite safe to make its way along those precipitous precipices where it oftentimes perambulates.
The truth of the matter seems to be that the dahu was a practical joke that guides played on gullible tourists, taking them all over crag and crevasse, looking for a creature who had no existence outside their imagination. The notion was so popular it spread to guides in the Pyrenees.
So, no, I don't suspect that you've ever hunted a dahu.