This is the female flicker in our backyard. I posted a photo of her the other day in Birds / Nesting peeking out of her nest hole. She had just finished bathing her belly feathers this morning - probably so she can get them nicely fluffed to keep the eggs warm.
A favorite spot for many of the birds to take a bath is the waterfall stone in our water garden. They stand in the fast running water before starting their dip and splash routine.