Icterus mesomelas

Geographic Range

Yellow-tailed orioles ( Icterus mesomelas ) are found in Central and South America (Monroe and Sibley 1993). They are found predominantly below 500 m altitude. There are five described subspecies: Icterus mesomelas mesomelas , Icterus mesomelas salvinii , Icterus mesomelas carrikeri , Icterus mesomelas taczanowskii , Icterus mesomelas xantholemus (Clemens 2007).

Icterus m. mesomelas and I. m. salvinii can be found in Central America. Icterus m. mesomelas can be found in the tropical southeast of Mexico, which extends from south Veracruz to the city of Oaxaca; they are also found in Belize and Honduras (Clemens 2007). Icterus m. salvinii is found in the Caribbean lowlands of Nicaragua, east Costa Rica continuing to extreme northwest Panama (Jaramillo and Burke 1999).

The other three subspecies can be found further south along the Pacific lowlands. Icterus m. carrikeri is found from Panama to northwestern Columbia and northwestern Venezuela. In Panama, the range extends along the Pacific slope from the Canal eastward and in the north it extends from the lowlands of Colombia northwards of the Santa Marta Mountains and the Magdalena Valley. Furthermore, the geographic range includes the east of Guajira, North of Santander and extends into the northwest of Venezuela (Jaramillo and Burke 1999). In Venezuela, yellow-tailed orioles are found around the Lake Maracaibo basin, in Zulia, Tachira and Merida (Ridgely and Tudor 2001).

Icterus m. taczanowskii is endemic to the Pacific lowlands of western Ecuador and northwest Peru (Clements 2007). In Peru, the range stretches from Piura in the north (Jaramillo and Burke 1999) to the Pacific Coast to Lambayeque. Their range is separated by the Andes mountain range, unlike the continuous distribution from north to south and then continues into the upper Maranon Valley and further south to La Libertad (Ridgely and Tudor 2001).This is the only part of South America where the range of I. mesomelas is disrupted.

Icterus m. xantholemus is known only from Ecuador. Although some experts indicate that these individuals may represent immature I. mesomelas (Clemens 2007), others propose that it could be a hybrid between two unknown species of Icterus (Sibley and Monroe 1990), others treat it as a valid species (Blake et al. 1968).

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Yellow-tailed orioles prefer tropical lowlands below 500 m elevation (Clemens 2007). They can be found in woodlands, clearings, and brushland. They are often found near stands of Heliconia plants, Manila hemp, or in agricultural areas, showing a clear preference for banana plantations. They inhabit areas near water and are the only Central American oriole that prefers swamps (Jaramillo and Burke 1999). They forage in pairs for insects, spiders, and fruits (Stiles and Skutch 1989).

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest

• Wetlands
• swamp swamp

• Other Habitat Features
• agricultural agricultural

Physical Description

Yellow-tailed orioles are medium-sized birds, ranging from 20 to 23.6 cm long (Howell and Webb 1995) and weighing around 70 grams (Stiles and Skutch 1989). This species is identified by the golden yellow color of their tail and stripe on their wing coverts. They differ from yellow-backed orioles ( Icterus chrysater ) in that the latter has yellow back, entirely black tail and no yellow on the wings. A yellow tail is found in all ages of this species. Other features that distinguish yellow-tailed orioles from other orioles are white markings on the wings, yellow shoulders, and bristly forehead feathers (Jaramillo and Burke 1999).

Like most tropical orioles , this species is sexually monomorphic: males cannot be differentiated from females based only on appearance. However, certain differences have been identified between adult, immature, and juvenile birds (Howell and Webb 1995).

An adult yellow-tailed oriole has dark brown eyes and a black down-curved bill; the black coloration continues to the lores and anterior auriculars giving the illusion of a black mask. This mask extends to the chin, throat and upper breast as a bib. In addition, the back and scapulars display the same black coloration. The neck has orange-yellow stripes which fade along the back. The tail is long, moderately graduated, and the uppertail coverts are yellow (Howell and Webb 1995). Finally, the legs and feet are a mixture of blue and grey (Jaramillo and Burke 1999).

Immature individuals have duller yellow bodies and olive-black backs. The rump and uppertail coverts are also olive, but the wings are dark brown, the tail is olive yellow (Jaramillo and Burke 1999).

Juvenile yellow-tailed orioles have dull yellow and olive heads with pinkish lower mandibles. The back and rump are olive brown (Howell and Webb 1995). The wings are olive with two thin yellowish wingbars. Juveniles resemble immature individuals, but lack the black lores and black bib (Jaramillo and Burke 1999).

Subtle variations can be seen among yellow-tailed oriole subspecies. Icterus m. mesomelas individuals have secondary edgings and the base of the tertials edges are consistently yellow. Icterus m. carrikeri individuals have shorter bills and less black coloration on the throat than I. m. salvinii , but can be paler orange instead of yellow. Icterus m. salvinii individuals have larger bills than I. m. carrikeri and more extensive black on the throat. In comparison to I. m. carrikeri , I. m. mesomelas individuals are more orange in color. Finally, I. m. taczanowskii individuals are characterized by secondary edgings and white wing panel. They are more yellow than I. m. mesomelas (Jaramillo and Burke 1999). The closest relatives of yellow-tailed orioles are Icterus pectoralis and the complex that includes Icterus icterus (Omland et al. 1999).

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Reproduction

The male usually sings from the top of the trees whereas the female replies from the nest. The song is characterized by repetitive whistle-like sounds, varying in the number of notes (Jaramillo and Burke 1999).

• Mating System
• monogamous monogamous

Females build a nest of vegetable fiber in the shape of a basket which may hang two meters up in a shrub (Stiles and Skutch 1989). Clutch size is two to three eggs which are light blue with brown spots (Jaramillo and Burke 1999). Yellow-tailed orioles prefer to nest at low to mid-levels in shrubs or trees (Howell and Webb 1995). Nesting for this species happens later in the year than any other local orioles and differs depending on the location: in Panama nesting is in April, in Oaxaca, Mexico and Colombia nesting is in the middle of June. Nesting sometimes extends into November (Davis 1972).

A single hybrid between an I. mesomelas and I. chrysater from Colombia has been studied, and it was proposed that the lack of mates in the area may have led to this hybridization (Olson 1983). This hybridization is noteworthy because the two species are quite distantly related for orioles (Omland et al. 1999).

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• oviparous oviparous

Nesting period and dependency on the parents differs across their range but, typically the incubation period last 14 days and the hatchling needs approximately 13 days of parental care in the nest (Jaramillo and Burke 1999).

• Parental Investment
• altricial altricial
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

There is no information on lifespan in the literature.

Behavior

Yellow-tailed orioles are secretive orioles, although they are conspicuous when singing on exposed perches. Yellow-tailed orioles prefer living in pairs or forming small groups and can join flocks of other oriole species (Howell and Webb 1995). Because this species is non-migratory pairs are likely maintained year round (Friedman et al., 2009).

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• territorial territorial
• social social
• colonial colonial

Home Range

Home range size is not reported in the literature.

Communication and Perception

The call of yellow-tailed orioles is a repeated nasal chew or cheuk and a harder chuk or chook . Duetting birds commonly perform rhythmic repetition of phrases (Howell and Webb, 1995). Duetting and elaborate female song is common in tropical orioles (Price et al., 2009).

• Communication Channels
• acoustic acoustic

• Other Communication Modes
• duets duets

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

The diet of yellow-tailed orioles includes nectar and invertebrates, such as spiders (Stiles and Skutch 1989). Although they prefer dense undergrowth, they forage at all levels and have been seen on flowering trees (Restall et al. 2006).

• Primary Diet
• omnivore omnivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

• Plant Foods
• fruit
• nectar

Predation

There are no predators of yellow-tailed orioles reported in the literature.

Ecosystem Roles

Yellow-tailed orioles prefer areas of dense vegetation, including agricultural land, such as banana plantations (Jaramillo and Burke 1999). Yellow-tailed orioles can aid in pollination and seed dispersal. They also forage on insects and can potentially protect plants from pest insects.

• Ecosystem Impact
• disperses seeds
• pollinates

Economic Importance for Humans: Positive

Yellow-tailed orioles feed on insects in agricultural land and may contribute to the well-being of crops such as bananas. Like other tropical birds, their existence promotes ecotourism and birding, making a significance contribution to the local economy.

• Positive Impacts
• ecotourism ecotourism
• research and education

Economic Importance for Humans: Negative

There are no known adverse affects of yellow-tailed orioles on humans, though they may feed on bananas and other fruit.

• Negative Impacts
• crop pest

Conservation Status

Because of their large range, which lacks significant fragmentation, and stable population sizes, yellow-tailed orioles are not considered vulnerable. They are considered a species of least concern by the IUCN.

Additional Links

Encyclopedia of Life

Contributors

Lucia Zegarra (author), University of Maryland, Baltimore County, Kevin Omland (editor), University of Maryland, Baltimore County, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Bird, J., S. Butchart. 2010. "The IUCN Red List of Threatened Species" (On-line). Icterus mesomelas. Accessed March 12, 2010 at www.iucnredlist.org .

Blake, E., J. Greenway, T. Howell, G. Lowery, E. Mayr. 1968. Icteridae. Pp. 149- 165 in Check-List of Birds of the World , Vol. 14. Cambridge: Museum of Comparative Zoology.

Clemens, J. 2007. The Clemens Checklist of Birds of the World . Ithaca: Cornell University Press.

Davis, I. 1972. A Field Guide to the Birds of Mexico and Central America . Austin: University of Texas Press.

Friedman, N., C. Hofmann,, B. Kondo, K. Omland. 2009. Correlated Evolution of Migration and Sexual Dichromatism in the New World Orioles (Icterus). Evolution , 63/12: 3269-3274.

Howell, S., S. Webb. 1995. A guide to the birds of Mexico and northern Central America . Oxford ; New York: Oxford University Press.

Jaramillo, A., P. Burke. 1999. New World Blackbirds The Icterids . New Jersey: Princeton University Press.

Monroe, B., C. Sibley. 1993. A World Checklist of Birds . New Haven and London: Yale University Press.

Olson, S. 1983. A Hybrid Between the Orioles Icterus chrysater and I. mesomelas. The Auk , 100: 733-735.

Omland, K., S. Lanyon, S. Fritz. 1999. A molecular phylogeny of the New World Orioles (Icterus): The importance of dense taxon sampling. Molecular Phylogenetics and Evolution , 12/2: 224-239.

Price, J., S. Lanyon, K. Omland. 2009. Losses of female song with changes from tropical to temperate breeding in the NewWorld blackbirds. Proceedings of the Royal Society B: Biological Sciences , 276: 1971-1980.

Restall, R., C. Rodner, M. Lentino. 2006. Birds of Northern South America . New Haven and London: Yale University Press.

Ridgely, R., G. Tudor. 2001. The Birds of South America Volume 1 The Oscine Passerines Jays and Shallows Wrens, Thrushes, and Allies Vireos and Wood-warblers Tanagers, Icterids, and Finches . Austin: University of Texas Press.

Sibley, C., B. Monroe. 1990. Distribution and Taxonomy of Birds of the World . New Haven: Yale University Press.

Stiles, G., A. Skutch. 1989. A Guide to the Birds of Costa Rica . New York: Cornell University.