The Lewis's Woodpecker (Melanerpes lewis) is a large North American species of woodpecker which was named by ornithologist Alexander Wilson for Meriwether Lewis, one of the explorers who surveyed the areas bought by the United States of America during the Louisiana Purchase.
The Acorn Woodpecker (Melanerpes formicivorus) is a medium-sized woodpecker, 21 cm long with an average weight of 85 g.