The line 'typical woodpecker flight' is often used in the literature. It is used to describe a bounding, undulating flight style. However, many woodpeckers do not fly in this way. The larger species in particular do not bound but rather move in a fairly straight, steady line, flapping in a manner not unlike that of a crow. Black Woodpecker in flight taken by Colin Brown, Hungary, August 2012.
Male (note all-red crown) Jamaican Woodpecker Melanerpes radiolatus. Photo of this island endemic taken by Neil Bowman. This species will raise 2 or 3 broods a year and its holes provide cavities for various parrots, martins and other birds.
This excellent monograph on Picoides pubescens by Gary Ritchison includes some great photos of North America's smallest woodpecker species. The book is fact-filled, with just about all the natural history of the species covered, but it is not overly scientific and so is a book for all fans of woodpeckers. Published by Stackpole Books, USA, in 1999.