Figure 1. In Ceará, two Amazilia taxa occur, namely A. f. nigricauda (this page) and the Versicoloured Emerald Amazilia versicolor nitidifrons.

Among the morphological differences between these taxa are the undertail-coverts, which are white with bronze spots in A. versicolor nitidifrons, and pure white in A. fimbriata nigricauda (best seen in fig. 2). Furthermore, nitidifrons has a dark subterminal band crossing the rectrizes, which is absent in A. fimbriata (see fig. 3, and compare with Mata et al. 2006, p. 281 fig. 9).

References: Grantsau 1988, Schuchmann 1999, Mata et al. 2006.

Figure 3.