I was very intent on shooting a new find - a very large, beautiful, Bee Fly of the Xenox genus -
when I heard the coo of a Roadrunner very close behind me. I turned around very slowly and here is what I saw!
By the way, did you know the Greater Roadrunner is one of the only animals known to attack rattlesnakes? Apparently pairs sometimes hunt rattlesnakes cooperatively.
One bird distracts the snake while the other sneaks up and pins its head. They kill it by bashing its head against a rock.

Three images.