Wolves help

I play xbox 360 minecraft. (beta 1.6.6 right now). My friend and i have made a huge world together. It is very plentiful in all kinds of animals. It is VERY plentiful in sheep. The downside is my friend and i have only found one wolf. We have been all over the world, and most of the map is jungle-like biome and is also well lit. Is there any way wolves will spawn due to our tamperment of the world?

Also we have been playing the map for about a month, still with only one wolf sighting.