Mottle-cheeked Tyrannulet

The mottle-cheeked tyrannulet (Phylloscartes ventralis) is a generally common, small species of bird in the family Tyrannidae, the tyrant flycatchers. It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay. == Taxonomy and systematics == Some early twentieth century authors considered the mottle-cheeked tyrannulet and what are now the Panama tyrannulet (P. flavovirens) and olive-green tyrannulet (P. virescens) as conspecific. The three are now treated by many authors as a superspecies. The mottle-cheeked tyrannulet has three subspecies, the nominate P. v. ventralis (Temminck, 1824), P. v. angustirostris (d'Orbigny & Lafresnaye, 1837), and P. v. tucumanus (Zimmer, JT, 1940). Some authors believe that the "recognition of subspecies may be unwarranted". == Description == The mottle-cheeked tyrannulet is about 12 cm (4.7 in) long and weighs about 9 g (0.32 oz). The sexes have the same plumage, and the subspecies also have essentially the same plumage as well. Adults have a short thin whitish supercilium, an indistinct broken whitish eye-ring, a dusky line through the eye, a wide whitish and dusky crescent below the eye, a dusky "moustache", and the eponymous whitish and dusky mottled cheeks. Their crown, nape, back, and rump are dark olive. Their wings are dusky with bright…