Spectacled Tyrannulet (Zimmerius) [XC693965]
by Peter Boesman from Chamicero del Perij\u00e1 Proaves Reserve, Cesar, Colombia (call)
Spectacled Tyrannulet (Zimmerius improbus) [XC331814]
by Nick Athanas from Cesar, Manaure, Serran\u00eda del Perij\u00e1, arriba de El Cinco, Colombia (song)
Subspecies
Paltry Tyrannulet (Zimmerius vilissimus) and Mountain Tyrannulet (Zimmerius improbus) (Sibley and Monroe 1990, 1993) are retained as separate species contra SACC (2006), who include improbus as a subspecies of Paltry Tyrannulet (Zimmerius vilissimus), pending the outcome of investigation into the taxonomy of this group by SACC.
Despite superficial resemblance to Phyllomyias, genus appears to be more closely related to Phylloscartes. This species was formerly placed in a separate genus, Tyranniscus, but exhibits plumage and morphological features (wing pattern, proportionally long tail and bill, and derived characters of both syrinx and palate) typical of present genus. Previously considered conspecific with Paltry Tyrannulet (Zimmerius vilissimus), but differs in plumage, voice and habitat.
The following 3 subspecies are recognised:
improbus (Sclater & Salvin, 1871) - Northern Colombia (Norte de Santander) and north-western Venezuela (Táchira, Mérida, Barinas). Considered by some authors to be a subspecies of Paltry Tyrannulet (Zimmerius vilissimus).
tamae (Phelps & Phelps Jr, 1954) - Northern Colombia (Santa Marta Mts) and western Venezuela (Sierra de Perijá and Paramo de Tamá, in Táchira).
petersi (Berlepsch, 1907) - Northern Venezuela from southern Lara east to Miranda. Considered by some authors to be a distinct species, Venezuelan Tyrannulet (Zimmerius petersi).
BirdLife International Species Factsheet