Icterus cayanensis
epaulet oriole

Epaulet orioles are distributed widely throughout the central and eastern portions of South America. Each of the five subspecies of Icterus cayanensis inhabit a different area.

For I. c. cayanensis, the range covers the Amazon basin and its borders stretching from the Guianas, excluding the coastal plains, to northeast Brazil, south to Beni in Bolivia, and east to Peru.

Icterus cayanensis tibialis has a range within eastern Brazil from Maranhao, east through Piauí and Ceará, and south through Pernambuco, Bahia, Espirito Santo, and Rio de Janeiro.

The range of I. c. valenciobuenoi is outlined by south Goias, west Minas Gerais, west Sao Paulo, and southeast Mato Grosso.

Icterus cayanensis periporphyrus is found from northern and central Bolivia to western central Mato Grosso.

Icterus cayanensis pyrrhopterus has a range that stretches from central Bolivia east to Parana in Brazil, and as far south as Buenos Aires in Argentina.

Although formerly considered conspecific, Icterus chrysocephalus (Moriche orioles) is now generally considered a distinct species. Mitochondrial DNA sequence analysis indicates that all these taxa are very closely related (Omland et al. 1999). ("Wikipedia Moriche Oriole", 2008; Jaramillo and Burke, 1999; Omland, Lanyon, and Fritz, 1999; Ridgley and Tudor, 1989)

Epaulet orioles generally can be found in edge and open forests, as well as woodlands. They have been observed in open forests, forest borders, savannas, palm savanna, deciduous woodlands, gallery forest, urban gardens, cerrado woodlands, chaco woodlands, and clearings. They also inhabit both humid and dry areas of their habitat. They prefer open woodlands with sandy ground in Surinam, and frequent the dense forests of the Andean foothills in Bolivia. (Jaramillo and Burke, 1999; Ridgley and Tudor, 1989)

Epaulet orioles have very little color on their bodies, with an all black body and a dash of yellow or chestnut on the shoulders. Their body shape is slender with a thin, lengthy, rounded tail and a thin bill that varies in length and curve based on location. The lack of color in the plumage makes it easy to distinguish epaulet orioles from other orioles and difficult to distinguish them from blackbirds. Yellow-shouldered epaulet orioles (I. c. tibialis) have yellow color on the lining of the wing and the chestnut shouldered epaulet orioles (I. c. pyrrhopterus) may appear completely black from a distance. In adult males the bill is pointed without any curve and the eyes are dark brown to dark reddish brown. Below the eye is slightly grey and the wing linings are black. The back is also all black, lacking any indication of a pattern. Female epaulet orioles closely resemble males. Juvenile birds resemble adults but their colors are more muted.

Icterus cayanensis cayanensis, also known as Cayanensis orioles, have yellow on the shoulders and black running along the tip of the yellow wing lining. One regional variation has yellow lining to the thighs, which are typically black. This variation is thought to be independent of the influence of the other subspecies because of its geographical distance from them.

Icterus cayanensis tibialis, yellow shouldered or yellow thighed orioles, have a yellow shoulder similar to I. c. cayanensis. Some have yellow wing lining and thigh color (as opposed to black). This is not true everywhere, populations in the north tend to have yellow on the thighs, those in the south have black thighs and dusky wings similar to I. c. valenciobuenoi. They also have a shorter bill and smaller body than I. c. cayanensis.

Icterus cayanensis valenciobuenoi, Valencio Bueno’s oriole has a dusky wing lining with yellow tip, and black thighs. The shoulder is an ochre-orange, slightly paler than that of the I. c. periporphyrus. It is said to be an intermediate between the yellow shouldered, northern subspecies, and the tawny/chestnut shouldered southern forms.

Icterus cayanensis periporphyrus, tawny shouldered oriole, is similar to I. c. pyrrhopterus, except that it is slightly paler. This subspecies has a smaller, thinner bill, the underwings and thighs are black and the wings are tawny or cinnamon.

Icterus cayanensis pyrrhopterus, chestnut shouldered oriole, is the darkest of the subspecies and can sometimes appear almost completely black. The wing lining is black and the shoulder is chestnut. The chestnut coloration may be caused by the same "phaomelanin" coloration found in North American orchard orioles (Icterus spurius) (Hofmann, Cronin and Omland, 2007). (Hofmann, Cronin, and Omland, 2007; Jaramillo and Burke, 1999; Ridgley and Tudor, 1989)

There is no information on lifespan in epaulet orioles. Other Icterus species live up to 12 years in the wild.

Epaulet orioles are quiet but active. They have been observed alone and in pairs, although their counterparts in Bolivia may sometimes join mixed canopy flocks. They eat insects as well as fruit and nectar and they typically forage around the top to middle areas of trees. They are known to hang from vines and jerk their tail fretfully as they forage. (Jaramillo and Burke, 1999)

Home Range

Home range sizes are not documented.

Like other birds, epaulet orioles use primarily visual and acoustic cues for communication and navigating their environment. Males sing to attract females and advertise territorial boundaries.

Epaulet orioles eat insects, fruit, and the nectar of flowers.

Adults are likely attacked by Accipter hawks. Eggs and nestlings are likely to be preyed on by a variety of birds, snakes, lizards, and mammals. However, specific information on predation is not reported in the literature.

There is little published information on ecosystem roles. Epaulet orioles are likely to disperse seeds of fruit trees, pollinate fruiting trees, and impact insect populations through predation. Shiny cowbirds (Molothrus bonariensis) parasitize their nests.

There is no documentation of negative impacts on humans. Populations may cause minor damage to fruit crops.

There is little available documentation of positive economic impacts on humans. Epaulet orioles are likely to play a role as pollinators. They can also impact ecotourism as this species is endemic to relatively few countries in South America.

Epaulet orioles are widely distributed. However, individual subspecies could become threatened in the future as a result of habitat destruction.

This species is quite different from North American Icterus in that juveniles and yearlings lack a distinct pattern in their first year. Yearling epaulet orioles have a muted version of the adult color pattern (K. Omland, personal observation). Males and females are predominantly jet black as adults, with different patches of color depending upon subspecies (Jaramillo and Burke, 1999).

The Icterus cayanensis complex is closely related to another South American oriole species, Icterus auricapillus, orange-crowned orioles (Omland et al. 1999). This whole group likely colonized South America from the Caribbean islands (Omland et al. 1999; Sturge, Omland et al. submitted). (Jaramillo and Burke, 1999; Omland, Lanyon, and Fritz, 1999)