''Willisornis'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of insectivorous

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped') which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their ...

birds in the antbird family, Thamnophilidae. These small, strongly

sexually dichromatic Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecious species, which consis ...

birds are native to

the Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectiv ...

and

Amazon rainforest The Amazon rainforest, also called the Amazon jungle or Amazonia, is a Tropical and subtropical moist broadleaf forests, moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin ...

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 ...

, and often follow army ants.

Taxonomy

The genus ''Willisornis'' was erected by the Brazilian ornithologists Carlos Agne and José Fernando Pacheco in 2007. The genus is named after the American ornithologist Edwin O'Neill Willis. The common scale-backed antbird had traditionally been included in the genus '' Hylophylax'', but is now known to belong to a different

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

. The name ''Dichropogon'' was used briefly instead, but this name is preoccupied by a genus of asilid flies (''Dichropogon'' Bezzi, 1910). The two species are: * Common scale-backed antbird (''Willisornis poecilonotus'') *

Xingu scale-backed antbird The Xingu scale-backed antbird (''Willisornis vidua'') is a species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is endemic to Brazil. Taxonomy and systematics What is now the Xingu scale-backed an ...

(''Willisornis vidua'') The two species were previously considered

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

. They were split based on the differences in their vocalization.

References

Bird genera Birds of the Amazon rainforest {{Thamnophilidae-stub