Spot-winged Falconet

This is a small, unique falconid endemic to South America, easily distinguished by its compact build and strikingly patterned plumage. Adults measure between 9.8 to 12.2 inches (25 to 31 centimeters) in length, with a wingspan of approximately 18.5 to 20.8 inches (47 to 53 centimeters), and weigh around 5.3 ounces (150 grams). Their upperparts are predominantly ashy-gray to grayish-brown with fine, dark vertical streaking. In flight, their most conspicuous diagnostic feature is a bright white rump, which contrasts sharply with a black tail marked with white spots and tips. The breast and belly are whitish or buff with heavy dark brown streaks. The facial pattern is distinctive, featuring a bold white supercilium, a dark eye-line, and a narrow black malar stripe. The iris is a vivid bright yellow, matching the color of the bare cere and the unfeathered legs.

Geographical distribution: This raptor is restricted to the southern cone of South America, occurring across central and southern Bolivia, western Paraguay, much of northern and central Argentina (extending south into northern Patagonia in Río Negro province), and occasionally in western Uruguay. Its range is closely tied to the xerophytic woodlands of the Chaco and Monte biogeographical provinces.

Habitat: It primarily inhabits semi-arid, arid, and xerophytic ecosystems. It is a characteristic resident of dry Chaco woodlands, thorny shrublands, Monte desert scrub, and transitional savanna-like areas with scattered trees. It shows a strong preference for open habitats containing tall perches, such as telephone poles, fence posts, and mature woody plants of the genera Prosopis and Larrea, which it utilizes for hunting and territorial scanning.

Feeding: It exhibits an opportunistic and generalist predatory diet that varies depending on seasonal prey abundance. A significant portion of its diet consists of large invertebrates, particularly beetles, grasshoppers, crickets, and spiders. It supplements this diet by hunting small vertebrates, including lizards, small rodents of the genera Akodon and Calomys, and small passerine birds that are typically ambushed on the ground or caught in brief aerial pursuits.

Behavior: It is typically observed singly or in breeding pairs. As a perch-hunter, it spends considerable time scanning its surroundings from exposed branches, utility wires, or fence lines. Its flight is rapid and direct, characterized by alternating series of quick wingbeats and short glides. It is considered a sedentary and resident species throughout its range, though some localized movements may occur during prolonged droughts.

Nesting: Rather than building its own structure, this bird employs a unique nesting strategy by occupying the large, communal twig nests of the Monk Parakeet (Myiopsitta monachus). It often forcefully evicts the parakeets from one of the nest chambers to claim it for breeding. It also utilizes old, abandoned nests built by other bird species like the Lark-like Brushrunner (Anumbis annumbi) or members of the genus Pseudoseisura. The female lays a clutch of 2 to 4 cream-colored eggs densely speckled with reddish-brown. Incubation lasts approximately 28 to 30 days, performed mainly by the female while the male provides food. The nestlings fledge after about 35 days.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List of Threatened Species. Although it occurs in low population densities and exhibits a patchy distribution, its overall population appears stable. The primary long-term threats to its populations are habitat loss and fragmentation caused by deforestation for agricultural expansion and intensive cattle ranching within the Chaco and Monte biomes.