The photo quality (unclear view to nest, and shooting into the sun) is not too good.
I watched a 6 foot snake climb about 50 feet up this tree, entered the first woodpecker nest, then made his way up to the second woodpecker hole in the tree. The woodpecker flew in just as about half of the snake was entering in the hole and he started pecking the snake to try to fight it off. The snake quickly entered the nest and turned around and started trying to bite the woodpecker every time it put its head to the hole. The battle went on for about 15 minutes, I could never get a clear shot due to the wind and cover. The snake finally retreated completely back into the hole and the woodpecker could not reach him from outside the nest, and couldn't go in because the snake would get him.
If I had my rimfire rifle I would have helped the woodpecker out! Darn Snake.