Melodious Blackbird

Male melodious blackbirds average 25.5 cm (10 in) long and weigh 98.3 to 102 g (3.5 to 3.6 oz). Females average 23 cm (9.1 in) long and weigh 83.4 to 95.9 g (2.9 to 3.4 oz). The species has a long tail and disproportionately large legs and feet. The sexes have the same plumage: Adults are entirely black with blue and purple iridescence. They have a dark brown iris, a black bill, and black legs and feet. Juveniles are a duller, non-glossy, brownish black.

The melodious blackbird is found from southern Tamaulipas in northeastern Mexico south on the Gulf of Mexico slope almost to the Isthmus of Tehuantepec and from there on both the Gulf/Caribbean and Pacific slopes through southern Mexico including the Yucatán Peninsula. Its range continues through Belize, Guatemala, El Salvador, Honduras, and Nicaragua. Most references either omit Costa Rica from its range or take its range only into the northern part of the country. However, a 2007 field guide to Costa Rican birds states it was "[f]irst recorded in March 1987, [and is] now widespread and fairly common". The guide's map shows it present in most of the country with the exception of the southern Cordillera de Talamanca. Another source extends its range through Costa Rica into Panama. The melodious blackbird inhabits a variety of semi-open to open landscapes in the tropical and lower subtropical zones. These include the edges and clearings of extensive forest, open pine woodlands, gallery forest, coffee plantations, and pastures, parks, gardens, and human-inhabited areas with scattered trees. Sources differ on its elevational range. Two state it is from sea level to 2,000 m (6,600 ft) and another takes it to 2,500 m (8,200 ft). It reaches 2,100 m (6,900 ft) in Costa Rica.

The melodious blackbird is omnivorous; its diet includes insects, other arthropods, small vertebrates, seeds, fruit, and nectar. It primarily forages on the ground, bobbing its head as it walks, but also feeds in all parts of trees to the canopy. It has been observed picking ticks and other parasites from cattle. It exposes prey in pine cones, clusters of leaves, and other items by "gaping" (opening its bill in the substrate). It usually forages in pairs or family groups but does form large flocks that sometimes include other icterids.