[5] The blue-mantled thornbill has three recognized subspecies, the nominate C. s. stanleyi (Bourcier, 1851), C. s. versigulare (Zimmer, 1924), and C. s. vulcani (Gould, 1852).

[6] Subspecies C. s. versigulare's entire upperparts (not just the back) reflect deep violet-blue, and the lower pink to violet of the gorget is narrower than in the nominate.

[6] The nominate subspecies of blue-mantled thornbill is found on both slopes of the Andes of Ecuador between the departments of Carchi and Azauy.

C. s. vulcani is found on the eastern Andean slope from southern Peru to Cochabamba Department in central Bolivia.

[6] The blue-mantled thornbill inhabits steep, rocky slopes with somewhat humid páramo grasslands and jalca vegetation.

The blue-mantled thornbill's calls have been described as "a descending squeaky twitter followed by a mellower upslurred note" and "a downslurred 'tseetsitsitsitsitr-whee-tsew' [with] variations.

[1] Though it is generally fairly common, it is locally under threat by destruction of Polylepis woodlands and conversion of natural grasslands to pasture.