Plumbeous Ibis

Characterized by a robust silhouette, this medium-to-large bird measures approximately 28 to 30 inches (71 to 76 centimeters) in total length. Its plumage displays a remarkably uniform plumbeous grey coloration, which can reveal subtle bronze or bluish iridescence when illuminated by direct sunlight. A highly diagnostic feature is its whitish to buff-colored forehead band, contrasting sharply with the bare, dark greyish-black facial skin surrounding the base of the bill and the eyes. The nape features a shaggy, bushy crest of grey feathers. Its long, decurved bill is dark greyish-black, and its sturdy legs are a striking bright pinkish-orange or red. The irises are a prominent orange-yellow.

Geographical distribution: Occurs widely across the lowland regions of central-southern South America. Its primary range encompasses the Pantanal of southwestern Brazil, the expansive Chaco biome of Paraguay and Bolivia, northern to central Argentina (extending south to the Buenos Aires and La Pampa provinces), and western Uruguay. It is mostly a sedentary resident throughout its range, although it may perform localized seasonal migrations driven by rainfall patterns and the cycle of wetland flooding.

Habitat: Inhabits open, low-lying freshwater wetlands, including seasonally flooded savannas, wet grasslands, marsh edges, shallow lagoons, and agricultural fields such as flooded rice paddies. It strictly avoids dense forested environments and deep water bodies, as it requires soft, damp substrates and low-lying vegetation to successfully walk and forage.

Feeding: Maintains a highly carnivorous and opportunistic diet. It utilizes its long, sensitive, curved bill to probe mud, damp soil, or shallow water, locating prey primarily by tactile detection. It consumes a diverse array of terrestrial and aquatic invertebrates, such as apple snails (Pomacea spp.), beetles, insect larvae, earthworms, spiders, and crabs. Additionally, it opportunistically preys upon small vertebrates, including frogs, tadpoles, small lizards, snakes, and shallow-water fish.

Behavior: Exhibits primarily diurnal and terrestrial habits. Unlike many other gregarious ibis species, it is generally solitary or found in pairs, though small, loose family groups may occasionally assemble. It walks with a slow, deliberate gait while foraging on the ground. When startled, it flies up to settle on high tree branches. It is well-known for its exceptionally loud, metallic, ringing vocalizations, which sound like a high-pitched trumpeting, typically uttered in flight or from prominent tree perches to assert territory.

Nesting: Breeds as solitary pairs rather than establishing large multispecies nesting colonies. It constructs a bulky, platform-like nest using dry twigs and branches, lining the interior cup with softer grasses and green leaves. These nests are built at significant heights, typically 25 to 50 feet (8 to 15 meters) above the ground, often in mature trees or palm species such as Copernicia alba. The clutch consists of 2 to 3 eggs, which are pale greenish-white mottled with brown speckles. Both parents actively share incubation duties and cooperate in feeding the chicks via regurgitation.

Conservation status: Listed as a species of Least Concern (LC) on the IUCN Red List of Threatened Species. Although its global population remains large and relatively stable, localized populations face persistent threats due to wetland drainage and degradation, agricultural expansion, deforestation, and the bioaccumulation of agrochemicals in farming areas where it regularly feeds.