Subspecies of White-shouldered Tanager (1 Viewer)

I have a question in the id forum that also hinges a little on taxonomy: which subspecies is found where on the Pacific slope of Costa Rica and how do they actually look (especially head)? Here is the link: http://www.birdforum.net/showthread.php?p=3479967#post3479967

Niels

Niels,

It seems there are problems with the ranges attributed by some sources to the Mesoamerican subspecies...

The sspp. were described as follows:

• Tachyphonus nitidissimus Salvin 1870 [OD]; type locality: Bugaba / district of Chiriquí = Pacific slope of Panama.
• Chlorospingus axillaris Lawrence 1874 [OD]; type locality: Volcán de Irazu = high up, but on the Caribbean slope of Costa Rica. (See also the range of the species [here].)

This seems consistent with the ranges given in Clements:

• Tachyphonus luctuosus nitidissimus - Pacific slope of sw Costa Rica and extreme w Panama
• Tachyphonus luctuosus axillaris - Caribbean slope of e Honduras to w Panama

...and by Hellmayr 1936 [here]:

• Tachyphonus luctuosus nitidissimus Salvin. CHIRIQUÍ WHITE-SHOULDERED TANAGER. [...] Range. - Tropical zone of southwestern Costa Rica (north to the Rio Grande de Pirrís, possibly to the Rio Grande de Tarcoles) and extreme western Panama (Bugaba and Divala, Chiriquí).
• Tachyphonus luctuosus axillaris (Lawrence). COSTA RICAN WHITE-SHOULDERED TANAGER. [...] Range. - Tropical zone of the Caribbean side of extreme western Panama (Almirante Bay region), Costa Rica, Nicaragua, and (?) southeastern Honduras (Segovia River).

...but in HBW (both in [HBW-Alive] and in the books), the ranges look like they were inverted:

• T. l. nitidissimus Salvin, 1870 – Caribbean coast from E Honduras S to NW Panama (Bocas del Toro).
• T. l. axillaris (Lawrence, 1874) – Pacific coast of Costa Rica (San José) S to Panama (W Chiriquí).

...and in H&M4 too:

• nitidissimus Salvin, 1870 - Caribbean coast of E Honduras to NW Panama (Bocas del Toro)
• axillaris (Lawrence, 1874) - Pacific coast of Costa Rica to W Panama (Chiriquí)

From central Panama eastwards (both slopes) to trans-Andean South America, south to Perú, the ssp is panamensis. From western Panama west/northwards, the sspp are slope-specific with, based on the above, axillaris on the Caribbean side, and nitidissimus on the Pacific side. As per Hellmayr, the females of these two races are similar (both with greenish rather than grey head), with axillaris a bit brighter yellow below than nitidissimus.

Thanks Laurent!

Niels

Niels,
Males T. luctuosus from SW Costa Rica have an orange crest that sometimes is highly visible. When shown, is as conspicuous as that of a Tawny-crested Tanager. Also, I think the white may be a little broader.

César

Thanks Cesar

Niels