About Myrmotherula pacifica Hellmayr, 1911
The Pacific antwren (Myrmotherula pacifica Hellmayr, 1911) measures 9 to 10 cm (3.5 to 3.9 in) in length and weighs 8.5 to 10 g (0.30 to 0.35 oz). It is a small bird with a very short tail. Adult males have a black and white streaked face. Their crown, back, and rump are black with white streaks, and they have a narrow white patch between the shoulders. Their tail is black, with white edges and white tips on individual feathers. Their wings are black, with white tips on the coverts and white edges on the flight feathers. Their throat, breast, and belly are white, and their flanks and crissum are grayer. Black streaks run from the throat onto the flanks and belly. Adult females have a buff to cinnamon-rufous face, crown, nape, and shoulders, with black streaks on the crown and nape. They do not have the white patch between the shoulders that males have. Their throat and the center of their belly are pale buff, and the rest of their underparts are orange-ochre; females have no streaks on their underparts. The Pacific antwren is found on both the Caribbean and Pacific slopes of Panama extending into Colombia; on the Pacific slope, it only occurs as far west as Panamá Province. Its range continues across central Colombia east to the Magdalena Valley and Cundinamarca Department, and extends south along the Pacific slope into western Ecuador, reaching as far south as Azuay Province. It inhabits the understorey and mid-storey of lowland and foothill evergreen forest, as well as shrubby secondary forest. It is typically found in shrubby areas, often along watercourses. It seldom occurs in mature forest interior, except in regrowing clearings. It also sometimes occurs outside of forested areas in gardens and plantations. In terms of elevation, most populations occur between sea level and about 800 m (2,600 ft). In Panama, it only reaches up to 500 m (1,600 ft), while in Colombia it is found locally as high as 1,200 m (3,900 ft).
