Gnorimopsar chopi chopi

Exhibits a robust and sleek silhouette covered in uniform coal-black plumage, which displays a distinctive silky blue or purplish iridescence when illuminated by direct sunlight. Adults reach a total body length of 21.5 to 25 centimeters, with measurements varying by subspecies, among which G. c. sulcirostris represents the largest individuals. The bill is strong, slightly decurved, matte black, and features a characteristic longitudinal groove along the lower mandible, a key diagnostic feature of this monotypic genus. The iris is an intense, almost imperceptible dark brown, while the legs and feet are sturdy and black, highly adapted for terrestrial foraging. There is no obvious sexual dimorphism, although juveniles can be distinguished by their duller, sootier plumage lacking the metallic gloss of the mature adults.

Geographical distribution: Occurs widely across the central and eastern regions of South America. Its geographic range encompasses extensive areas of eastern and central Brazil (from Maranhão southwards to Rio Grande do Sul), eastern Bolivia, the entirety of Paraguay, northern and northeastern Argentina (extending down to the provinces of Buenos Aires and Córdoba), and northern Uruguay. This broad distribution highlights a significant ecological plasticity, allowing the species to settle across various South American biomes.

Habitat: Shows a clear preference for open and semi-open landscapes. It is commonly found in savannas, pastures, agricultural fields, palm groves, degraded forest edges, and the shrubby vegetation of the Cerrado and Caatinga formations. It exhibits a high tolerance for anthropogenic environments, frequently utilizing pastures and crop fields, while strictly avoiding dense, continuous rainforests like the Amazon basin or humid montane forests.

Feeding: Maintains an opportunistic and strictly omnivorous diet. It feeds heavily on invertebrates, such as beetles, grasshoppers, caterpillars, and spiders, which it actively searches for while walking on the ground. It also supplements its diet with small vertebrates, including small lizards and frogs. Seasonally, it incorporates a large proportion of vegetable matter, consuming grass seeds, agricultural grains (such as maize and sorghum), wild fruits, and occasionally flower nectar from native trees and shrubs.

Behavior: Displays highly gregarious habits outside the breeding season, forming noisy flocks that can exceed one hundred individuals, often mixed with other icterid species. It is renowned for its extremely complex and melodious vocal repertoire, consisting of loud, metallic, flute-like whistles uttered from prominent perches at the top of tree canopies. It is also known to mimic environmental sounds. During flight, it exhibits a vigorous and direct wingbeat. It is a diurnal species that travels daily between communal roosting sites and feeding grounds.

Nesting: The breeding season takes place primarily from October to January. Unlike many other icterids that weave complex hanging nests, this species is an opportunistic cavity nester. It frequently nests in natural tree cavities, hollow fence posts, or takes over and refurbishes abandoned nests of the rufous hornero (Furnarius rufus) or woodpeckers. The inner nest is a rustic cup made of dry grass, rootlets, and occasionally mud. The female lays 4 to 5 eggs, which are pale blue or greenish-blue, decorated with dark brown or black squiggles and spots. Incubation lasts around 14 days and is performed mostly by the female, although both parents actively cooperate in feeding and defending the nestlings, which fledge after approximately three weeks.

Conservation status: Listed as Least Concern (LC) on the IUCN Red List, owing to its vast distribution range and stable population trends. Nevertheless, local populations face threats from habitat loss due to agricultural expansion and, notably, from illegal trapping for the wild bird trade, driven by its highly prized singing abilities, which has led to localized declines in parts of its range.