Woodpecker genera

[Gentoo]

I know I've mentioned this before in a few threads here and there. However I want to see how much information anyone has regarding the pied woodpeckers. I know the AOU list all of them in the genus picoides, however the BOU uses Dendrocopos for all except the three-toed woodpeckers. (speaking of this did they split the Three-Toed Woodpecker in two species? If so than there are three species with three toes). The Japonese seem to follow the AOU on this as well.

Has anyone seen any papers on this subject? I tend to follow the BOU on this; for example on any of my list the Hairy Woodpecker would be Dendrocopos villosus. I understand this was the genus it was in and only a few Americans use it today.

[cuckooroller]

Shonn,
Just a general comment and that will not really satisfy you I am certain. Relatively little has been done with the taxonomical arrangement of Picidae since the family monograph by Short 1982 The Woodpeckers of the World. Most for the moment accept, and probably more by convenience than real evidence, the splitting of the New World species in Picoides, and the Old World species, exception being made for tridactylus, in Dendrocopos. Among the problems for this woodpecker tribe (Campetherini) phylogenetically speaking is the final destination of genus Veniliornis which would appear to cluster near some of the Picoides, e.g. Hairy Woodpecker, and which genus should probably be shifted out of the present tribe Colaptini and into Campetherini. The difficulty with a final determination of the relationship of Dendrocopos and Picoides is in large part due to the paucity of research regarding the Asian Dendrocopos. However, it would appear that the three three-toed Woodpeckers would appear to be most closely related to some of the smaller Asian Dendrocopos, e.g., D. kizuki, D. canicapillus, D. moluccensis, D. maculatus, and D. temminckii. The uncertainty is also reflected in the determination by Nigel Collar in retaining that one of the races now in D. maculatus, i.e. ramsayi, should be retained more closely related to D. temminckii, but for which he uses the binomen Picoides ramsayi. So, I am sure some one else might give you a more to your point answer, but this to open a small window on the complexity of the issues involved.

[Xenospiza]

OK, I know I am repeating things – with a few additions.
The African Dendropicos and the "large" Eurasian Dendrocopos seem to be related to each other ("Old World Spotted"). This group includes the Okinawa Woodpecker ('Sapheopipo' noguchii), which is really a dark relative of the White-backed Woodpecker.
Most American Picoides and South American Veniliornis form a group as well ("New World Spotted") .
The "small" Eurasian Dendrocopos (Lesser Spotted and those Oriental "Pygmy Woodpeckers") are related to the three-toed woodpeckers.
It's just not totally clear (or unambiguous) yet... I guess if you call all these "Picoides" (the oldest name available) no one can argue you are doing something wrong (unlike with any other classification).