That's so sad!
Maybe a petition to have the videos removed? I doubt YouTube will want to damage their reputation - if enough people speak up about it, they might take it down.
But at the moment it's getting so many views and is therefore obviously beneficial to YouTube. The views need to stop, but people are thoughtless; they want to watch a cute animal and a lot of them will have no idea of the cruelty involved. Perhaps if someone made an information video about why it is wrong, and linked it as a video response to the initial video. Or else provide information via the comments on YouTube (this would increase the views though...).
At least it has got publicity via a UK newspaper, so hopefully word will spread now. As it is an endangered species I'm sure there will be many people ready to campaign on its behalf. I hope so.
I wish I could think of what more we could possibly do.