Thectocercus acuticaudatus koenigi

Characterized by its slender silhouette and distinctly graduated, pointed tail, this medium-sized Neotropical parrot exhibits an average length of 13 to 15 inches (33 to 38 centimeters) and a body mass ranging between 110 and 170 grams. Its plumage is predominantly a vibrant bright green, which turns paler and more yellowish on the underparts. The most striking diagnostic feature is the rich opalescent blue wash that covers the forehead, crown, lores, and cheeks, varying in intensity depending on age and subspecies. It features a conspicuous, bare yellowish-white orbital ring surrounding an orange-red iris. The bill is strong and hooked, classically bicolored in the nominate subspecies, with a pale horn-colored upper mandible and a contrasting dark gray or blackish lower mandible. In flight, the under surface of the long tail feathers reveals a beautiful reddish-maroon hue on the inner webs, providing an elegant flash of color.

Geographical distribution: This bird presents a disjunct distribution across South America. Northern populations inhabit the arid zones of Colombia and Venezuela, including Margarita Island. A much broader distribution spans the southern half of the continent, covering eastern and southern Brazil (ranging from Piauí and Bahia down to Rio Grande do Sul), the dry chaco of Bolivia, the entirety of Paraguay, northern and central Argentina (reaching as far south as Buenos Aires and La Pampa provinces), and occasionally northern Uruguay.

Habitat: It primarily frequents dry and semi-arid biomes, avoiding dense, humid tropical rainforests such as the core Amazon. It is a defining avian element in the Chaco, Caatinga, and Cerrado ecoregions. The species is commonly found in deciduous woodlands, thorn scrub, gallery forests, wooded savannas, and disturbed agricultural landscapes. It also adapts well to cliffside environments and suburban areas, utilizing urban parks containing exotic fruiting trees that provide ample food and nesting opportunities.

Feeding: Its diet is strictly granivorous and frugivorous, showing a high level of adaptability to seasonal food resources. It feeds extensively on grass seeds, cactus fruits, berries, flower buds, and nectar. In agricultural regions, it frequently targets commercial crops such as maize, sorghum, and sunflowers, which sometimes leads to conflicts with local farmers who view them as agricultural pests. Seeds from native woody legumes and trees of the genus Celtis also represent a significant portion of its nutritional intake.

Behavior: Highly gregarious and vocal, this species is typically observed in active, noisy flocks of 10 to 30 individuals, though these groups can swell to several hundred at communal roosting sites or abundant feeding grounds. Its flight is rapid and direct, accompanied by loud, screeching contact calls that maintain flock cohesion. It exhibits nomadic tendencies, migrating locally to track water and seasonal fruiting events. During the hottest hours of the day, flocks remain quiet and hidden within the dense canopy to avoid detection by predators.

Nesting: Breeding activity occurs mainly between November and March in the southern hemisphere. This cavity-nester utilizes natural hollows in mature trees or abandoned woodpecker holes, and has occasionally been recorded nesting in crevices along rocky cliffs. The female lays a clutch of 3 to 4 matte white eggs. The incubation period lasts approximately 24 to 26 days and is performed solely by the female, while the male provides food. The chicks are altricial and naked at birth, and are cared for by both parents through regurgitation until they fledge at about 50 to 60 days of age.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List due to its extremely large geographic range and overall stable population trends. However, localized populations experience ongoing pressure from habitat fragmentation due to agricultural expansion and historically high levels of exploitation for the domestic and international pet trade, leading to its listing under CITES Appendix II to monitor commercial international shipments.