Hi Tony,
I have always been a keen birder, not a fanatic, just keen. Always adds an extra dimension in the Game Reserves.
Anyway, I bought myself a 500mm f4 the other day and loaded into the vehicle this morning, just in case. We went out looking for landscapes and got to this low-level bridge, which I was hesitant to attempt. As I was doing a u-turn I saw the bird with the snake. I quickly changed lenses and managed to get a few shots before he swallowed the snake a flew off.
We then watched these two ladies crossing the river. They had obviously done it before because they held onto each other and made it through quite easily. Always something interesting in Africa! I love it!
Chris I cheated a bit with the second picture. I used the new Radial Filter Tool in Lightroom 5 to emphasise the DOF.
Matt, I have no idea how long it takes, the snake was certainly still moving around pretty vigorously, so it was not even dead yet!
William
PS. Tony, the main reason for the 500mm is because in November I have been invited to one of those exclusive lodges in Kruger National Park where I have been "guaranteed" numerous leopard sightings a day! Once I get some decent leopard pictures I can die a happy man!!

William