Yellow-winged Blackbird

Overview

The yellow-winged blackbird, Agelasticus thilius, is a species of bird in the family Icteridae. It is found across South America, with three distinct subspecies inhabiting specific regions from Peru to Argentina.

Identification

• Males are almost entirely black with yellow marginal, lesser upperwing, and underwing coverts, while females are brown with dusky streaks and a buff supercilium.
• The species is sexually dimorphic, with males averaging 17.9 cm in length and 33.5 g in weight, and females slightly smaller at about 29 g.
• Both sexes possess a black bill, black legs and feet, and a brown iris.
• Vocalisations include variable trills of 3–7 notes, a whistled warble, and a sharp 'chep' call.

Habitat

The bird primarily inhabits marshes, wetlands, and associated reed beds, though it also occurs in nearby grasslands and croplands. Its distribution is disjunct, with subspecies found in the Andean wetlands of Peru and Bolivia, as well as coastal and southern regions of South America.

Diet

Feeding primarily on aquatic insects and seeds, the bird also consumes other invertebrates such as spiders, crustaceans, and mollusks. It forages in flocks within marshes, grass, and cultivated fields.

Did you know?

The female builds a cup nest primarily from marsh vegetation, often using the sedge Schoenoplectus californicus, and incubates two to four eggs alone for 12 to 13 days.