''Theristicus'' is a genus of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s in the family

Threskiornithidae The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however, recent genetic studies have cast doubt on this arrangement, and ha ...

. They are found in open, grassy habitats in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. All have a long, decurved dark

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Pl ...

, relatively short reddish legs that do not extend beyond the tail in flight (unlike e.g. ''

Eudocimus ''Eudocimus'' is a genus of ibises, wading birds of the family Threskiornithidae. They occur in the warmer parts of the New World with representatives from the southern United States south through Central America, the West Indies, and South Ame ...

'' and ''

Plegadis ''Plegadis'' is a bird genus in the family (biology), family Threskiornithidae. The genus name derives from Ancient Greek ''plegados'', "sickle", referring to the distinctive shape of the bill. Member species are found on every continent except A ...

''), and at least the back is grey.

Taxonomy

The genus ''Theristicus'' was erected by the German naturalist

Johann Georg Wagler Johann Georg Wagler (28 March 1800 – 23 August 1832) was a German herpetologist and ornithologist. Wagler was assistant to Johann Baptist von Spix, and gave lectures in zoology at the Ludwig Maximilian University of Munich after it was moved t ...

in 1832 with the

black-faced ibis The black-faced ibis (''Theristicus melanopis'') is a species of bird in the family Threskiornithidae. It is found in grassland and fields in southern and western South America. It has been included as a subspecies of the similar buff-necked i ...

as the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. The name is from the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

''theristikos'' meaning "of reaping". The genus contains four species.

Taxonomy

References

Further reading