Here's a diagram that shows the relative size of a great grey owl's body to its feathers. It's hosted on Wikimedia commons, labelled "Cross sectioned taxidermied Great Grey Owl, Strix nebulosa, showing the extent of the body plumage, Zoological Museum, Copenhagen."
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.