This is a Harrier Hawk at Moholoholo Rehab Centre.
Sadly this bird only has one foot (I'm not 100% sure how it lost the other one - possibly to an infection), but it does perfectly fine anyway. I've never seen it fall over.
He's a very timid bird though - if you go anywhere near him he tend to feak out and fly to the other side of the enclosure. Which can be a bit unnerving if you happen to be in his path. He's pretty though.
I know this isn't a great shot, but I like the bird, so I'm uploading it anyway.