Icterus laudabilis

Geographic Range

The St. Lucia oriole ( Icterus laudabilis ) is endemic to St. Lucia, an island within the Lesser Antilles located in the Caribbean Sea. There are no other resident orioles in St. Lucia, however, Baltimore and Orchard orioles may appear in the region as vagrants. (Jaramillo and Burke, 1999; Raffaele, 1998)

• Biogeographic Regions
• neotropical neotropical
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

St. Lucia orioles inhabit mountain rainforests, dry coastal scrub forests, primary and secondary forests, the edges of certain plantations (such as banana citrus and coconut) and mangroves (particularly those that adjoin coastal scrub). They appear to prefer humid mountain forests to the dry coastal scrub forests. Inhabited regions range from sea level up to 700m elevation (Jaramillo and Burke, 1999; Hoyo et al, 2011).

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• rainforest rainforest
• scrub forest scrub forest
• mountains mountains

• Other Habitat Features
• agricultural agricultural

Physical Description

St. Lucia orioles are black throughout with the exception of russet orange plumage located on the rump, belly, shoulders and vent. There is an abrupt transition between the black and the colored regions. It has been suggested that females have duller orange or orange-yellow colored regions when compared to males (Jaramillo and Burke, 1999; Hoyo et al, 2011). These birds have a slim, sharp and relatively long beak. The culmen, or upper ridge of the beak, is nearly entirely straight. The shape of the beak is useful as it allows them to strip bark while foraging and weave their hanging "pendent" nests (Jaramillo and Burke, 1999; Hoyo et al, 2011, Bond, 1993). St. Lucia orioles grow to 20 to 22cm in head to body length and have an average mass of 36.9 grams (both sexes included in these measurements). According to measurements in Jaramillo and Burke, adult males have an average wing length of 98.7mm while the average wing length among adult females is 94.0mm. Measurements from samples used gave males a longer tarsus (region from the bird's "knee" to its "ankle"), tail and culmen on average (Jaramillo and Burke, 1999; Raffaele, 1998). St. Lucia orioles can be distinguished from male Baltimore orioles by the absence of white wing bars and the lack of orange expanding to the tail. Immature St. Lucia orioles are mostly chestnut in color with golden olive colored plumage seemingly in place of the russet orange plumage (Raffaele et al, 1998).

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

• Sexual Dimorphism
• sexes alike

Reproduction

St. Lucia orioles are solitary breeders most likely monogamous, a trait that is prevalent among members of the genus Icterus (Hoyo et al, 2011; Jaramillo and Burke, 1999).

• Mating System
• monogamous monogamous

In the wild, parents have been observed feeding juveniles between late June and August. Based on this information, Jaramillo and Burke predicted the nesting season to be between April to early June. However, more studies are needed before on their annual behavioral patterns before a strong conclusion can be made. The female members of the species lay and incubate 2 to 3 white and brown spotted eggs. The nest is woven from plant fibers and suspended by stitching fibers through perforations in banana leaves or occasionally coconut palms. More research on territoriality and other reproductive behaviors is needed (Jaramillo and Burke, 1999; Hoyo et al, 2011).

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

Adults care for their young in the nest and at least several weeks after they fledge from the nest. Chicks are fed insects, spiders, and fruit pulp. There is limited information on parental investment, indicating a need for further study (Hoyo et al, 2011).

• Parental Investment
• altricial altricial
• male parental care male parental care
• 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
• pre-independence
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifespan/Longevity

More research is needed on the lifespan of this species.

Behavior

Usually only one or two St. Lucia orioles are observed at a time in the wild. More recent accounts state that no more than four adults have been observed together at a time (Babbs et al. 1988). Members of the Icteridae family are recognized for their wide range of foraging adaptations and high degree of intelligence. St. Lucia orioles are able to feed on both insects and fruits due to these foraging adaptations. This species has been observed to strip bark to forage using a technique that is analogous to that used by Jamaican orioles ( Icterus leucopteryx ) (Babbs et al, 1999; Jaramillo and Burke, 1999).

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary

Home Range

St. Lucia orioles are endemic to the island of St. Lucia. They appear to be nonmigratory (Jaramillo and Burke, 1999).

Communication and Perception

St. Lucia orioles have 2 calls. One is a hard chwee and another a soft chup. Recordings of these calls may be found online (Bond, 1993; Chartier, 1994). The St. Lucia oriole's song is a sequence that is composed of varying 2 second long and "sweet" whistles. These whistles are produced in an order in which they are mostly ascending. Their song may contain up to 7 notes and has been described as pleasant by listeners. More research is needed to determine whether or not female St. Lucia orioles sing as many other tropical oriole species do, such as the Bahama and Puerto Rican orioles (Jaramillo and Burke, 1999; Odom et al. 2015).

• Communication Channels
• acoustic acoustic

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

Food Habits

St Lucia orioles are able to feed on nectar, fruits, insects, and other arthropods due to their foraging adaptations. They use their beak to probe at and remove bark from trees to reveal hidden insects and other prey. St. Lucia orioles eat primarily bananas and cultivated mangoes in terms of fruit. Per Hoyo et al, chicks are fed insects, spiders and fruit pulp (Fraga et al, 2011).

• Primary Diet
• carnivore carnivore
  • insectivore insectivore
  • eats non-insect arthropods
• herbivore herbivore
  • frugivore frugivore
  • nectarivore nectarivore
• omnivore omnivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

• Plant Foods
• fruit
• nectar

• Foraging Behavior
• stores or caches food stores or caches food

Predation

There is no information on predators of St. Lucia orioles.

Ecosystem Roles

More research is needed on the ecosystem roles of St. Lucia orioles. It is likely that they play a role in seed dispersion as fruits are a central part of their diet.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

St. Lucia orioles are considered among the six endemic bird species that are sought after by bird watchers on St. Lucia. Their local name is "carouge" and they are considered an uncommon species.

• Positive Impacts
• ecotourism ecotourism

Economic Importance for Humans: Negative

There are no negative impacts of St. Lucia orioles on humans.

Conservation Status

According to the IUCN, this species is currently classified as "Near Threatened" and is believed to have a stable population of roughly 1,000 individuals. Due to its small global range and small population this species may be uplisted to "Vulnerable" if population numbers were found to be declining. Population trends are poorly known and more research is needed to determine the effects of many potential threats on this species' population. These threats include pesticide spraying, habitat loss, parasitism by shiny cowbirds ( Molothrus bonariensis ) and harassment by spectacled thrushes ( Turdus nudigenis ) (Birdlife International, 2010). Shiny cowbirds may pose the most interesting threat out of those listed. As obligate brood parasites, shiny cowbirds lay their eggs into the nests of other birds and assume no parental care of chicks. The host species will then feed and shelter the shiny cowbird hatchling as if it were its own offspring. Brood parasites often have adaptations such as shorter incubation periods, ability to remove host eggs, or faster nesting growth, which allow them to outcompete host chicks for resources. Shiny cowbirds have a broad host specificity and threaten other tropical oriole species such as the Bahama oriole ( Icterus northropi ) and Montserrat oriole ( Icterus oberi ). Since 1900, the range of shiny cowbirds has expanded from Venezuela up to most of the West Indies and southern Florida. Its increase in range and population size is associated with both human expansion of agricultural lands and clearing of tropical forests. Shiny cowbirds are considered a "pest" in St. Lucia and approximately 3/4 of oriole broods are either partially or entirely made up of shiny cowbirds. The effects of heavy cowbird parasitism on St. Lucia populations cannot be elucidated without further research (H. temple in litt. 2005; IUCN, 2012; Lowther, 2011).

Other Comments

Research performed by the Omland lab at University of Maryland Baltimore County placed St. Lucia orioles within oriole "clade A." While the exact relationships are not definitively known, St. Lucia orioles are most closely related to other Caribbean and Southern American oriole species. The placement of two South American oriole species, ( Icterus cayaneusis and Icterus dominicensis ) and within clade A provides strong evidence their ancestors originated from the Caribbean, in a case of island to mainland colonization (Omland et al, 1999; Sturge et al., 2009).

Furthermore, phylogenic analysis of clade A with many closely related but separate oriole species that reveals a pattern of rapid radiation, which is characteristic of speciation across island archipelagos (Omland et al, 1999; Sturge et al., 2009).

Although the island of Martinique is located only 27 km away from St. Lucia, the Martinique oriole ( Icterus bonana ) does not seem to be the species most closely related to St. Lucia orioles based on mitochondrial DNA analysis (Sturge et al., 2009; Fraga et al, 2011).

Additional Links

Encyclopedia of Life

Contributors

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

References

Bond, J. 1993. Birds of the West Indies . New York: Houghton Mifflin Company.

Fraga, R. 2011. Handbook of the Birds of the World . Barcelona, Spain: Lynx Edicions.

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

Odom, K., K. Omland, J. Price. 2015. Differentiating the evolution of female song and male-female duets in the New World Blackbirds: Can tropical natural history traits explain duet evolution?. Evolution , 69: 839-847.

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: 224-239. Accessed April 01, 2016 at http://www.ncbi.nlm.nih.gov/pubmed/10381325# .

Orians, G. 1985. Blackbirds of the Americas . Seattle and London: University of Washington Press.

Raffaele, H., W. Wiley, G. Garrido, A. Keith, J. Raffaele. 1998. A Guide to the Birds of the West Indies . Princeton, New Jersey: Princeton University Press.

Sturge, R., F. Jacobsen, B. Rosensteel, R. Neale, K. Omland. 2009. Colonization of South America from Caribbean Islands confirmed by molecular phylogeny with increased taxon sampling. The Condor , 111: 575-579.

2012. "Icterus laudabilis" (On-line). The IUCN Red List of Threatened Species. Accessed March 28, 2016 at http://www.iucnredlist.org/details/22724153/0 .

2016. "St Lucia Oriole Icterus laudabilis" (On-line). Accessed March 28, 2016 at http://www.birdlife.org/datazone/speciesfactsheet.php?id=9700 .