Eurasian collared dove
The grey-headed woodpecker is in length, has a wingspan of and weighs around . The male of the nominate subspecies has a grey head with a red forecrown. There is a black line across the lores and a narrow black moustache stripe. The back, and wing are green. The breast and underbody are pale grey. The folded primaries are barred brown-black on grey-white. The female lacks the red forecrown but has fine black streaks on the crown. The widely distributed "Picus canus jessoensis" is very similar to the nominate subspecies but is slightly greyer and less green. The Chinese subspecies "Picus canus guerini" has a black nape patch and a greenish underbody. The subspecies "Picus canus hessei" is similar to "guerini" but is more golden green above and a deeper green below. The race on the island of Sumatra, "Picus canus dedemi", differs markedly from the other subspecies in having reddish rather than green above, and red, green and grey below. It has a black crown and nape. 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.