Characterized by a marked sexual dimorphism and a medium-sized body measuring approximately 6.7 to 7.1 inches (17 to 18 centimeters) in length. This species, biologically designated as Leistes superciliaris, weighs between 33 and 40 grams. The breeding male displays a striking, mostly sooty-black plumage that contrasts brilliantly with a vibrant scarlet-red throat and breast. Its most prominent diagnostic feature is a long, highly visible white superciliary stripe extending from the bill base down to the nape. Underflight feathers showcase bright white underwing coverts, which create a flashing effect when the bird is in motion. In stark contrast, the female is cryptically colored, featuring a streaked brownish upper body, a pale throat, a buff-colored eyebrow, and sometimes a faint, delicate wash of pale pink or orange on the breast. Its conical, robust bill is dark gray, adapted for a varied diet.
Geographical distribution: Spreads extensively across several regions of South America. Its breeding grounds are situated in northern and central Argentina, throughout Uruguay, across southern and central Paraguay, and into the southern and eastern states of Brazil, particularly Rio Grande do Sul and Paraná. Following the breeding period, during the southern hemisphere´s winter, southern populations migrate northward to overwinter in eastern Bolivia, central Brazil (primarily the Cerrado and Pantanal biomes), and occasionally reaching the southeastern lowlands of Peru.
Habitat: Inhabits primarily open and semi-open lowland ecosystems. It is commonly found in native grasslands, wet meadows, shrubby savannas, pastures, and agricultural fields, particularly fallow crop fields and grain stubble. This bird shows a high degree of tolerance to anthropogenic modifications, successfully occupying landscapes cleared for cattle ranching, provided that patches of dense, tall herbaceous vegetation are preserved to offer adequate shelter.
Feeding: Exhibits an omnivorous diet with a strong insectivorous preference during the nesting season. Its primary food source consists of invertebrates, including beetles, grasshoppers, caterpillars, spiders, and ants, which it captures by walking and foraging methodically on the ground. During the non-breeding season, it shifts its diet significantly to consume grass seeds and leftover agricultural grains, utilizing its powerful conical bill to easily crack open hulls and process seeds.
Behavior: Displays highly gregarious tendencies outside the breeding period, congregating in large foraging and roosting flocks that can exceed one hundred individuals, frequently associating with other icterid species. During the breeding season, males become intensely territorial and engage in a spectacular courtship display: they ascend vertically several yards into the air while singing a buzzy, wheezy song, then glide slowly downward with their wings raised in a distinctive V-shape toward a prominent perch, such as a tall shrub or fence post, to monitor their territory.
Nesting: Constructs its nest directly on the ground, carefully concealing it deep within dense grass tussocks or tall herbaceous vegetation. The nest is a deep, sturdy cup woven from dry grass fibers and fine roots, occasionally featuring a loose dome-like cover that helps camouflage the structure from aerial predators. Females lay a clutch of 3 to 5 eggs that are greenish-white or pale blue, speckled with dark reddish-brown spots. This species is a frequent host of the brood-parasitic shiny cowbird (Molothrus bonariensis), which regularly deposits its eggs in the nests of this host for rearing.
Conservation status: Classified under the Least Concern (LC) category on the IUCN Red List. Although the global population is considered stable and the species occupies a very vast geographical range, localized populations face threats from the intensive use of agricultural pesticides, rapid habitat destruction through mechanized farming that crushes ground nests, and the ongoing conversion of native South American grasslands into monoculture plantations.
Compilation and publication: EcoRegistros – 24/07/2026