Interesting, though I'm not convinced all these splits would go through if using BSC (but some certainly will, notably
P. nigrogenis). Regardless of the species concept, I find some of the morphological information they present problematic, especially for bill and legs. Why they generally choose to rely on old specimens (where bare part colours often are highly unreliable) and old publications (where often equally unreliable) is odd, considering that the true bare part colours for most taxa (the only exception being
xinguensis) now are well-known by ornithologists working in the specific regions, and the issues could therefore have been avoided by checking with local ornithological authorities. For example, according to their appendix A, the bill colours are (my comments in brackets after each species - all comments are for adults; bill colours are different in juv's, as described in two of the species in post #9 here:
http://www.birdforum.net/showthread.php?t=140312):
*
P. coronata; pearly gray. (upper mandible very light greyish, almost white, with dark grey culmen; lower mandible very light greyish, almost white)
*
P. dominicana; pearly gray (upper mandible blackish; lower mandible very light greyish, almost white).
*
P. capitata; yellow. (orange).
*
P. cervicalis; black + yellow. (upper mandible blackish; lower mandible pale pinkish-flesh, sometimes faintly tinged orange, with a narrow blackish tip).
*
P. gularis; black + yellow. (upper mandible blackish; lower mandible pale pinkish-flesh, sometimes faintly tinged orange, with a narrow blackish tip).
*
P. nigrogenis; black + yellow. (upper mandible blackish; lower mandible very light greyish, almost white, with a narrow blackish tip. Very light greyish occasionally replaced by very light flesh-coloured).
*
P. baeri; black. (upper mandible blackish; lower mandible very light greyish, almost white, with a narrow blackish tip).
*
P. xinguensis; black. (never seen it, don't know; reputedly like
baeri).
Some of the differences noted above are of course minor, and others are described/shown more accurately in their appendix B/fig. 3, but several of them are not. Comparably, according to them, some species have grey tarsi, while others have black (here disregarding the strikingly different
P. capitata). In reality, they're dark greyish, to the extend that it easily could be described as black, but there are no obvious differences between the species.
On an entirely separate issue I found it interesting that
P. coronata and
P. capitata are listed on CITES app. II. I am well aware that this appendix includes species not threatened at present, but I'm surprised anyone seriously would think these two are even remotely at risk of becomming threatened in the future.
