Theristicus is a genus of birds in the family Threskiornithidae. They are found in open, grassy habitats in South America. All have a long, decurved dark bill, relatively short reddish legs that do not extend beyond the tail in flight (unlike e.g. Eudocimus and Plegadis), and the back is grey.
Taxonomy
The genus Theristicus was erected by the German naturalist Johann Georg Wagler in 1832 with the black-faced ibis as the type species. The name is from the Ancient Greek theristikos meaning "of reaping". The genus contains four species.
Genus Theristicus – Wagler, 1832 – four species
Common name
Scientific name and subspecies
Range
Size and ecology
IUCN status and estimated population
Plumbeous ibis
Theristicus caerulescens (Vieillot, 1817)
south-western Brazil, especially in southern Mato Grosso and Rio Grande do Sul; Paraguay, especially in the Chaco and in the Paraguayan section of the Parana Basin; Uruguay; north-eastern Argentina and northern and eastern Bolivia
Size:
Two subspecies
T. c. caudatus (Boddaert, 1783)
T. c. hyperorius Todd, 1948
northern and central South America in Colombia, Venezuela, the Guianas and Brazil
Size:
Habitat:
Diet:
LC
Black-faced ibis
Theristicus melanopis von Berlepsch & Stolzmann, 1894
central Argentina and Chile
Size:
Habitat:
Diet:
LC
Andean ibis
Theristicus branickii (Gmelin, 1789)
western South America
Size:
