Puna Ibis

The Puna Ibis (Plegadis ridgwayi) is a South American member of the family Threskiornithidae, named in honor of the American ornithologist Robert Ridgway. It closely resembles the Glossy Ibis and White-faced Ibis in overall appearance, sharing the characteristic dark, iridescent plumage of the genus, though it tends to be somewhat smaller and shows subtle differences in the extent of facial skin color and iridescence. Adults display chestnut and purplish-brown body plumage with greenish and bronzy gloss on the wings and back. The bill, as in all Plegadis ibises, is long and strongly decurved.

This species is restricted to the high Andes and surrounding highlands of South America, where it inhabits the puna zone — a high-altitude grassland and wetland biome found primarily between approximately 3,000 and 5,000 meters above sea level. It occurs in Peru, Bolivia, northwestern Argentina, and northern Chile, with the core of its range centered on the altiplano. The species favors bofedales (high-altitude peat bogs), shallow lakes, marshy grasslands, river margins, and flooded fields at high elevation.

The Puna Ibis feeds on a variety of aquatic and terrestrial invertebrates found in its high-altitude wetland habitat, including insects, earthworms, and aquatic invertebrates. Like other ibises in its genus, it forages by probing soft substrates with its curved bill, using tactile sensory receptors to locate hidden prey in mud and shallow water. Flocks often forage together in marshy areas adjacent to Andean lakes.

Breeding biology of the Puna Ibis is less well documented than that of its more widespread relatives, but it is known to nest colonially in freshwater marshes, constructing platform nests of vegetation among emergent reeds and rushes. Clutch sizes and incubation periods are presumed to be similar to those of related Plegadis species. The species is generally resident within its high-altitude range and does not undertake major migrations, though some altitudinal movement may occur seasonally.

The Puna Ibis is classified as Least Concern by the IUCN, with a population estimated in the low tens of thousands. Ongoing threats include wetland degradation, drainage of bofedales for livestock and agriculture, and hunting in some parts of its range.