White-faced Whistling Duck

About the white-faced whistling duck

The white-faced whistling duck is a whistling duck that breeds across sub-Saharan Africa and much of South America — an unusual, disjunctive distribution for a single species, occurring naturally on two continents separated by an ocean. It has been suggested that humans may have helped transport the species to some of its far-flung locations. It was formally described by the Swedish naturalist Carl Linnaeus in the 1766 twelfth edition of his Systema Naturae, originally under the name Anas viduata, with a type locality of Cartagena, Colombia. It's now one of eight species in the genus Dendrocygna, a name that combines the Greek dendron ("tree") with the Latin swan genus Cygnus. The species name viduata is Latin for "widowed" or "in mourning," and no subspecies are recognized.

As its name suggests, the bird has a distinctive white face, set off by a black neck and head, a long grey bill, a long head, and longish legs. The back and wings are dark brown to black, the underparts black with fine white barring on the flanks, and the neck chestnut-colored. Males and females look alike. The amount of white on the face varies regionally — birds with more black coloration are typically found in western Africa, where rainfall extends longer through the year and shortens the dry season. Juveniles resemble adults but show a much less contrasted head pattern.

Behavior and diet

The white-faced whistling duck is highly gregarious. At favored sites, flocks of a thousand or more birds arriving at dawn make for an impressive sight, and the species lives up to its name with a clear, three-note whistling call that makes it a noisy presence wherever it gathers. It is largely a resident species, though it does make local movements that can cover 100 km or more.

Its diet in the wild consists of seeds and other plant food, taken from the freshwater lakes and reservoirs it favors. For breeding, the nest is a simple depression on the ground or built within reed beds. A clutch numbers 6 to 12 eggs, incubated by both the male and the female, and the eggs hatch after 26 to 28 days. Both parents attend to the ducklings after hatching, typically keeping them hidden within reed cover, and the young fledge after about two months. Chicks are covered in dark down above and yellow down below.

Range and habitat

The white-faced whistling duck occupies a broad but disjunctive range spanning sub-Saharan Africa and much of South America. It favors freshwater lakes and reservoirs with plentiful vegetation, where it feeds on seeds and other plant matter. Because of its wide range, the species carries many local common names, including "irere" and "guiriri."

Conservation status

The white-faced whistling duck is rated Least Concern on the IUCN Red List, in a 2016 BirdLife International assessment. It is an abundant species, and it is one of the species covered by the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA), an international treaty aimed at protecting migratory waterbird populations and their habitats.