About Psarocolius atrovirens (Orbigny & Lafresnaye, 1838)
This is the dusky-green oropendola, with the scientific name Psarocolius atrovirens (Orbigny & Lafresnaye, 1838). Adult males reach a total length of about 42 cm (17 in), while adult females are smaller at approximately 33 cm (13 in). The two sexes are similar in overall shape and appearance. Their plumage is mostly dark brownish-green or blackish-green, with a rufous-brown rump and crissum, the undertail coverts that surround the cloaca. The beak is greenish-white, a small number of yellow feathers may be present on the head, and the iris can be brown or blue; blue irises may only occur in older individuals. The closely related russet-backed oropendola (Psarocolius angustifrons) partially shares this species' range, but can be distinguished by having more rufous-colored upperparts, a yellow forehead, and an olive-green head that contrasts with its back and wings. The dusky-green oropendola is found on the eastern slopes of the Andes Mountains, with a range stretching from Huánuco Province in central Peru south to Santa Cruz Department in Bolivia. It inhabits montane forests and forest edges at elevations between 800 and 2,600 m (2,600 and 8,500 ft) above sea level, and generally occurs at higher altitudes than the russet-backed oropendola. The diet of the dusky-green oropendola likely includes insects such as moths, other arthropods, small vertebrates, nectar, and fruits. Its breeding season runs from October to December, and it breeds in small colonial colonies.
