Those cameras are all very nice. They will all create very pleasing images. In fact I doubt you would see much difference between the three of them except for the 6.3 mp's of the fuji. For nature/wildlife you will want the longest zoom of the three, That would be the canon or the sony at 432mm each. The canon features image stabelization and better optics than the sony, so for me it is the clear winner here.

I would also consider the Panasonic DMC-FZ30.

I hope this helps.