Looks like the baby is waving :)

Baby gorilla climbing onto the mother's back.

The Canon EF 500mm f/4L IS Prime. I don't own this lens (it retails for $5500!) When we arrived at the Bai it was there, available for use, which made me very glad I had a Canon EOS SLR. With the teleconverter installed this setup has a 700mm focal length (digital crop factor on my Rebel XTi makes this a 1120mm 35mm equivalent).