This is the mate of a male tiger who was missing the day I took this picture because it was undergoing surgery for a urinary tract infection. She appeared stressed because he was missing.

The photo was taken at the Sacramento, California zoo with a Nikon D4 using the 80-400mm lens at 1/400 f8 at ISO 5000 on 8 Oct 2013

Unfortunately at a later date the male died apparently from medical problems similar to that which it had undergone surgery for.

I might add the photo was taken through a chain link fence but I was able to get so close to the fence with the lens that it is sufficiently out of focus and thus effectively unnoticeable.