When shooting animals in captivity or in the wild, you just never know which animals might be out and which might be hiding. Some of the really cool animals (the big cats, elephants and others) can be hard to shoot, since much of the time they are behind thick windows that is dirty and scratched, or large fences that distract from the final image. You end up shooting a lot and hoping to get one or two that you really like.
A lion waits in the shadows. Photo by Tim Stanley