''Epimachus'' is a genus of birds-of-paradise (Paradisaeidae) that includes two species, found in the highland forests of

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...

. They are the largest members of the family. The common name "sicklebill" refers to their long, decurved,

sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting succulent forage chiefly for feeding livestock, ...

-shaped bill. Sicklebills often associate with astrapias, which are superficially similar but have a short, straight bill and blunt-tipped tail, and the male's wings hiss in flight. The species in the genus ''Epimachus'' are often referred to as "long-tailed" sicklebills, when describing them collectively as a genus. The other sicklebills, genus ''

Drepanornis ''Drepanornis'' is a genus of bird-of-paradise found in forests of New Guinea. They have long decurved sickle-like bills and an overall brown plumage. The genus is sometimes considered a subgenus of '' Epimachus'', but the two members of ''Drep ...

'', are referred to as the "short-tailed" sicklebills. Ironically, the two genera are not closely related. There may also be confusion with the birds of the same name that belong to the

hummingbird Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics ar ...

family, found in the Americas.

Taxonomy

The genus ''Epimachus'' was introduced in 1816 by the French naturalist

Georges Cuvier Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in na ...

for the

black sicklebill The black sicklebill (''Epimachus fastosus'') is a large member of the birds of paradise family, Paradisaeidae. This species is found throughout most of central New Guinea and the Vogelkop region to the northwest in montane forests at altitude ...

. The genus name is from the

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

επιμαχος (''epimakhos'') meaning "equipped for battle" (from ''makhomai'' "to fight"). In 1972, the genus was merged with the genus ''Drepanornis'', but separated again in 1998. A phylogenetic study placed ''Epimachus'' in a clade that includes ''

Paradigalla The genus ''Paradigalla'' consists of two species of birds-of-paradise. Both are medium-sized black birds with blue and yellow facial wattles. The name of the genus is derived from two words, the ''Paradisaea'' and '' Gallus'', the junglefow ...

'' and '' Astrapia'', implying that the long, curved bill has been acquired independently in ''Epimachus''. According to the same study, the ''Drepanornis'' species are closely related to the Twelve-wired bird-of-paradise,

Standardwing bird-of-paradise The standardwing bird-of-paradise (''Semioptera wallacii'') also known as Wallace's standardwing or as the standardwing is a species of bird-of-paradise. It is the only member in monotypic genus ''Semioptera''. Etymology George Robert Gray of th ...

, superb birds-of-paradise, and the riflebirds. The two species of ''Drepanornis'' as well as the two species of ''Epimachus'' separated about 10 and 7 mya, respectively. While the two species of ''Drepanornis'' occupy different elevations in low- and mid-montane forests, the two species of ''Epimachus'' are altitudinal replacements in mountain forests; these two cases could represent old cases of altitudinal

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution withi ...

Species

Description

Both species of ''Epimachus'' are

sexually dimorphic Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

. The males of these birds are highly eccentric, with hyperbolically long, saber-like, black tails that reach around alone. They also feature two pectoral fan-like plumes on each side of the breast, which they bring up over their heads during their displays. There is extensive green/purple iridescent highlights found on the head and back of the adult male; additionally, blue gloss is present on the tail. The females of both species both have barred underparts, olive-brown upperparts and relatively long tails, though not as extensive as the males' tails.

Distribution and habitat

Sicklebills are endemic to

, sympathetically inhabiting areas of

montane rainforest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

and

cloud forest A cloud forest, also called a water forest, primas forest, or tropical montane cloud forest (TMCF), is a generally tropical or subtropical, evergreen, montane, moist forest characterized by a persistent, frequent or seasonal low-level cloud ...

along the central mountainous axis of the island. Brown sicklebills are more common, inhabiting mid and upper-mountain forests, including mossy

, above the elevations of other sicklebills. Black sicklebills are more rare and inhabit the transition from mid-mountain to cloud forest, occasionally forest edges.

References

Bird genera Taxa named by Georges Cuvier {{Paradisaeidae-stub