These two holes I am fairly certain were done by the Pileated Woodpecker based on their size. I should have placed something into the hole as a reference, but consider I could stick my fist into the opening. This is a large tree. Large enough you could not wrap your arms around and not be able to touch your hands together, if that helps any. To hear these large woodpeckers hammer on trees is as if someone is taking an ax to the tree. Normally the holes are high up so I was surprised to come across this at eye level.
Here is a picture of the Pileated Woodpecker I swiped off the Interent as I do not have a picture of one.
But I do have a video of one at work I made last year. Look closely and you'll be able to see the wood dust fly in the sunlight.