Shiny hunting in Friend Safari?

So I've been on a hunt for a shiny Dragonaire for three days now just using REs in a friend safari that hasn't yet added me back. So I've been encountering tons and tons of Dragonaires and Gabites nonstop, only occasionally closing my DS to charge it or take a break for a bit. I haven't run into one yet and was wondering if there was a reason for that other than just the rarity of shiny Pokemon? Didn't want to waste any more time if I can try to hunt down a Pontya or something instead. Any advice/help would be appreciated as I'm still semi-new to the safari scene.

Thanks!