Pin-tailed manakin

The pin-tailed manakin is a monotypic species within the genus Ilicura, with no known subspecies.[2] This bird was first named in 1850, without indication of etymology, by a German zoologist named Heinrich Gottlieb Ludwig Reichenbach on in a work titled “Avium Systema Naturale”.[3] Its protonym is Pipra militaris.[4] The common name pin-tail manakin in English is based on its tail shape.[3] The first part of its scientific name, Ilicura militaris, stems from the root “ilex” or “ilicis”, referring to the botanical species (Ilex aquifolium) of which the tail feathers’ pointed central veins resemble the thorns of the leaves, and the Greek root “oura” meaning tail.[3] The second part of the scientific name, militaris, comes from the Latin roots mille, milia, millia, or militaris, referring to thousands or a large quantity. It may also come from the Latin root "militar", giving distinction to the pointed tail's appearance.[3] In Brazil, the common name is Tangarazinho, but is also known as saira-ilicuria, “cracker”, and the rainbow tangara in some regions of Santa Catarina.[3] The relationship between the pin-tailed manakin and the rest of its closest relatives within the family Pipridae is relatively unknown, although there is strong correlation between certain aspects of their courtship displays.[5]

Males measure 12.5 cm (4.9 in), while the females measure 11 cm (4.3 in) from tail to beak at full maturity.[6] There is clear sexual dimorphism between mature adults of this species, but can be nearly impossible to identify the sex for certain if they do not have the adult male colorations, as both juvenile males and females resemble each other.[7] All pin-tailed manakins share some common traits: a forking tail at the very end of their rectrices, a slightly elongated forehead, brownish black legs, and bright yellow-orange irises.[8] Adult male pin-tailed manakins have a slightly longer tail, with a very uniquely pigmented red fore-crown and rump, black wings with green secondaries, and a white chest that extends from their under-tail coverts all the way to their auriculars.[9] Females are an olive-green color everywhere except for their grey neck and auriculars, and their crème colored chest extending to its under-tail coverts [9]

The pin-tailed manakin is endemic to Brazil, specifically inhabiting the Atlantic Forest range from the State of Bahia to the State of Rio Grande Do Sul.[11] Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montane forests.[6] They are not very commonly spotted within their range, but spend their time within the lower and middle strata of the rainforests.[6] Their nests are built very similar to a cup, and holds a clutch of 2 to 3 eggs.[6] Their distribution has not been studied in depth, and as a result there is not a firm grasp of where their populations may inhabit. Three pin-tailed manakins have been collected by the Museu Nacional in Rio de Janeiro that has their location of collection tagged as Nova Veneza, which is more inland and Northern than previously recorded, providing evidence for a possible extension of their range.[11]

There is little to no mention of the pin-tailed manakin in culture or relationship to humans.

The pin-tailed manakin is not globally threatened, but is uncommon to fairly uncommon within the Atlantic Forest range of Brazil.[12] According to the IUCN, the pin-tailed manakin is rated as Least Concern with an unknown quantity of individuals, suspected to be in decline from habitat destruction, but needs more research conducted to provide an accurate conservational account.[14]

The pin-tailed manakin's characteristically vibrant red fore-crown and rump come from the carotenoid pigment rhodoxanthin.[15] Rhodoxanthin is a uniquely rare red pigment amongst most animals, as it is created endogenously from the organism itself.[16] Rhodoxanthin is a carotenoid hypothesized to be created from the 4 keto-carotenoids that are found in the diet of the pin-tailed manakin, and then transformed into stereoisomers of rhodoxanthin to be used as pigmentation in the feathers through some unknown process.[15] Rhodoxanthin is unique because it can produce a wide range of reds and yellows due to its ability to reflect and absorb light from longer wavelengths—which most other pigments are incapable of.[16]

One mutant has been found of the pin-tailed manakin species in which the normally red fore-crown and rump were replaced with an orange and yellow color.[15] This mutant is hypothesized to have a mutation that does not allow for the 4 keto-carotenoids to be transformed into rhodoxanthin, or for the production of its stereoisomers.[15] Research on rhodoxanthin in pin-tailed manakins has revealed much about its pigmentary capabilities, but more research is still needed to identify the biological processes that lead to the phenotypic red color in these bird's feathers.

• Snow, Barbara K. & Snow, D. W. (September 1985). "Display and Related Behavior of Male Pin-tailed Manakins" (PDF). Wilson Bulletin. 97 (3): 273–282.