Focus on Azure-shouldered Tanager

Azure-shouldered Tanager Thraupis cyanoptera is a scarce and often elusive Atlantic Forest endemic that birders sometimes struggle to distinguish from the much more abundant Sayaca Tanager Thraupis sayaca. However, given reasonable views they can be told apart fairly easily.

Azure-shouldered is slightly but noticeably larger and bulkier than Sayaca Tanager, but the size is not always apparent unless the two species are seen side by side. Much more obvious is the general colouration - Azure-shouldered Tanager is turquoise above with brighter turquoise outer edges to the flight feathers, tertials and greater coverts, and a contrasting duller turquoise grey below (this contrast is sharply defined even on the head and neck). Sayaca Tanager is a very variable grey-blue and generally concolorous above and below, with turquoise tones restricted to outer edges of the wing feathers. On Azure-shouldered Tanager the electric blue lesser coverts are diagnostic but not always visible (especially on 1st winter birds), and the blackish lores and black extending very slightly behind the eye forming a very short faint eye-stripe (visible at very close range) are another key feature. Azure-shouldered also shows a slightly heavier bill (that is often blackish on the upper mandible and greyish on the lower mandible, but not always), but both species show very dark (blackish) inner webs to the tertials, upper wing coverts and flight features on the closed wing.

Sayaca Tanager is abundant in forest edge and semi-open habitats and very conspicuous, even in cities, whereas Azure-shouldered Tanager is a scarce forest interior species that tends to stick to the canopy and is therefore much harder to find. Last July I spent some time at Andy and Cristina Foster's superb photo hide at their Serra dos Tucanos lodge in Rio de Janeiro state, and was able to study this Near-threatened species in some detail. These photos illustrate the features nicely.

Azure-shouldered Tanager Thraupis cyanoptera, Serra dos Tucanos, July 2011.
Note the contrast between the turquoise nape and crown and the grey blue face,
ear coverts and underparts. The electric blue lesser coverts are not always
visible.

Azure-shouldered Tanager Thraupis cyanoptera, Serra dos Tucanos, July 2011.
The blackish lores are a key identification feature when distinguishing from Sayaca
Tanager, but are not often mentioned or illustrated in field guides.

Azure-shouldered Tanager Thraupis cyanoptera, Serra dos Tucanos, July 2011.
The blackish lores create a rather aggressive facial expression (cf. Sayaca
Tanager below).

Azure-shouldered Tanager Thraupis cyanoptera, Serra dos Tucanos, July 2011.
The faint dark eye-stripe is easier to see in this shot of the same bird in the shade.
Note the dark upper mandible.

Azure-shouldered Tanager Thraupis cyanoptera, Serra dos Tucanos, July 2011.
Note the turquoise forehead, crown and nape contrasting sharply with the greyer
ear coverts and neck. The black inner webs to the tertials, coverts and primaries
and black primaries contrast vividly with the turquoise outer webs.

Sayaca Tanager Thraupis sayaca, REGUA, RJ state, July 2011. Note the grey blue
plumage, with turquoise tones restricted to the outer edges of the wing feathers.
The lores are concolorous with the rest of the face, isolating the dark eye. The
race found in south-eastern Brazil, T. s. sayaca, has no white in the wing.

The main contact call of Azure-shouldered Tanager is a simple, sharp, high-pitched downslurred seep (reminiscent of Redwing Turdus iliacus), whereas Sayaca Tanager has a shorter and rather almost squeaky call which has upwards deflection in the middle. The sonograms below clearly show the difference.





The songs are quite similar, both being a high-pitched, squeaky notes, but Azure-shouldered is faster, more repetitive and more continuous. Compare below.





The taxonomy of tanagers (Thraupidae), as with many Neotropical bird families, is currently in a state of flux. Azure-shouldered Tanager and Sayaca Tanager are traditionally both placed in the Thraupis genus along with 7 other species. But molecular studies have revealed that the Thraupis is actually paraphyletic (have more than one common ancestor) and consists of 2 clades. Azure-shoudered Tanager, despite having a similar morphology, is actually part of a different clade to Sayaca Tanager, and so will probably be moved to a different or new genus at some point. In the meantime, the Brazilian Committee of Ornithological Records (CBRO), rather confusingly, has moved all species currently in Thraupis into the Tangara genus, effectively removing the Thraupis genus altogether. However, other authorities (including the AOU) have yet to adopt this taxonomy and so I've remained faithful to the traditional classification here.