A Greater Spotted Woodpecker - or at least that is what they are called here in the UK. Excellent photo - in its own right, as well as an example of a natural history photograph. At first I thought you had rotated the image, but that would mean the woodpecker was head down!
I like the B&W for this woodpecker "hanging around" shot. Most of the woodpeckers here are the red-bellied variety, and a few bigger pileated ones are around occasionally. I like the way you included enough of the branch to give it a sense of scale of the bird. You didn't post shooting info with the photo, so I am not sure what to make of the noise in the sky in this shot. I am wondering if it was shot at high iso to get better shutter speed, or if it is cropped from a larger image to get the composition. I am a bit of a fan of noise, especially in B&W images, as it reminds me of the 35mm century.
Nicely composed. I like the lines of the limbs and lighting. I had a pair of woodpeckers last year that pecked all the grapefruit on my tree. I thought they just ate bugs!