Grey-headed woodpecker Concern" rating is primarily based on the large distribution of the species. The grey-headed woodpecker is long and weighs . Specimens of the more widespread of the two Eastern subspecies, "P. c. jessoensis", are usually a little larger and heavier than individuals from the type locality. On average, it is somewhat smaller and lighter than the European green woodpecker. In the field, this distinction in size is difficult to make. Its size is approximately that of a Eurasian collared dove. Grey-headed woodpeckers have uniformly olive green upperparts, transitioning across the neck to a light grey, the head being that latter
How the Snake Lost Its Legs of each animal's structures and organs, ecology and behaviour. The main text is supported by an accurate glossary and thorough index. Glossary terms are printed in boldface in the text, a helpful feature, while the glossary, like the text, is cited to the key research papers on which the book is based. The book thus provides a wide overview of evo-devo, with guidance on how to read more deeply on any chosen aspect. The book was published by Cambridge University Press as a paperback in 2014 (). The main text is 148 pages, with an 8-page glossary of evo-devo, and