Animal Diversity Web

Geographic Range

The Jamaican blackbird is an endangered species endemic to its namesake island, Jamaica. It is restricted to the Blue Mountains in the east and the Cockpit Country in the west. Evolutionarily, this species is a part of the grackles and allies within the New World blackbirds. Subsequent phylogenetic research has placed Nesopsar in the same group as Agelaius and Dives, but it still in its own distinct lineage. Although there is not enough information to reliably estimate the current population size, the species is considered endangered because of its restricted range and particular habitat needs. ("Important Bird Areas in the Caribbean -Jamaica", 2016; Barker, et al., 2013; Lanyon and Omland, 1999)

• Biogeographic Regions
• neotropical
  • native

• Other Geographic Terms
• island endemic

Habitat

Preferred habitat of the Jamaican blackbird is very specific and the range is highly fragmented as a result. The Jamaican blackbird is usually confined to areas of above 575 m and is rarely seen in lowland areas. Like many other species, the abundance and presence of food is indicative of habitat. Its local name “wild pine sergeant” is indicative of its preference for the epiphytic plant locally called the "wild pine" (a bromeliad). Optimal Jamaican blackbird habitats are described as being places with abundant precipitation and heavy epiphytic growth. These include wet limestone forest, lower montane rainforest, montane mist forest, and elfin forest. However, the species apparently avoids ridge forest of higher elevation or exposed sites. Jamaican blackbirds are found in Cockpit Country, John Crow Mountains, and Dolphin Head, which boast wet limestone forests, and the Port Royal Mountain, Hardwar Gap and, Blue Mountain Peak, which are montane forests. ("Important Bird Areas in the Caribbean -Jamaica", 2016; Bond, 1993; Cruz, 1978; Downer and Sutton, 1990; Jamarillo and Burke, 1999)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest
• mountains

• Range elevation

  575 to 2256 m

  1886.48 to 7401.57 ft

Physical Description

The Jamaican blackbird has been described as looking and behaving like a black oriole. True to this description, it is a medium-sized bird of around 7 to 8 inches long with entirely black plumage, but with a blue gloss noticeable on the head, upper-parts, and wing coverts. This blue gloss is entirely absent on the belly. The wing primaries appear slightly browner than the rest of the body. The adult has a black bill with dark eyes; its legs and feet are also black. Its bill, although proportional to its body, is comparatively longer and narrower than those of other Icteridae. There is a high probability that this adaptation along with gaping have helped the bird to more efficiently forage into crevices. Compared to other blackbirds, the tail is short and slightly rounded. The Jamaican blackbird is arboreal and thus should might be expected to show stiffening of the tail feathers as characteristic of other arboreal climbing birds. However, this is not the case. The tarsometatarsal length of the Jamaican blackbird is shorter relative to other blackbirds and approaches the length typical of tree trunk foragers. The juvenile sports a similar coloration to that of the adult’s but with a looser texture to the plumage. Its plumage also lacks the indicative blue gloss and instead appears more brown in color. The adult male is about 5% larger than the female, but their average mass is approximately 41 g. The wing length for the adult male measures 92 to 102 cm while the female measures 94.5 to 101 cm. (Bond, 1993; Cruz, 1978; Downer and Sutton, 1990; Jamarillo and Burke, 1999; Raffaelle, et al., 1998; Raffaelle, et al., 2003)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger

• Average mass

  41.1 g

  1.45 oz

• Range length

  18 to 23 mm

  0.71 to 0.91 in

Reproduction

The Jamaican blackbird is socially monogamous. Nesting season lasts from May to July. Pairs apparently roost a distance of approximately 50 to 100 feet from each other. (Jamarillo and Burke, 1999; Orians, 1985; Skutch, 1996)

• Mating System
• monogamous

The nest is a bulky cup that is built at an average height of 8 m, the lowest height being 6 m and the highest 11 m above the ground in the lower canopy. The nest site is not well hidden when compared to those of other blackbirds of the Americas. It is made of epiphytic fibers, thin dark roots of air plants and rootlets. The nest is like that of the marsh-nesting blackbirds including Agelaius but differs in building materials. Several nests were found in trees that grew slanted so that the trunk was almost horizontal. Typically, two sparsely spotted and scrawled eggs are laid. (Jamarillo and Burke, 1999; Orians, 1985; Raffaelle, et al., 1998; Raffaelle, et al., 2003; Skutch, 1996)

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

• Breeding interval

  Jamaican blackbirds breed once annually

• Breeding season

  Jamaican blackbirds breed in May and June.

• Average eggs per season

  2

• Average time to hatching

  14 days

The female Jamaican blackbird builds the nest and incubates the eggs as well. On the other hand, the male often would stand guard near the nest to ward off any possible intruder. Males do feed nestlings, although less than the female. However, the male may bring larger items than the female. (Jamarillo and Burke, 1999; Skutch, 1996)

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

Lifespan/Longevity

There is little to no information on the longevity of this bird.

Behavior

The species is not as well as known as other island blackbirds. Jamaican blackbirds are highly territorial and observed to be very particular about its habitat, including wet montane forests. Instead of the frequency-modulated songs typical of many forest dwelling birds, Jamaican blackbirds instead have a buzzy song that is common among blackbirds. They also employ a flight-song display, which is rarely seen in forest-dwelling birds but is observed among birds that dwell in open spaces. Because of the lack of a “forest-dwelling” song, Jamaican blackbirds have developed two flight song displays, which are sung and performed by both sexes. At daybreak, the male is active thirty to forty minutes before the female. It is at this time that he performs the flight song throughout his territory while repeating the dzik call. The female will respond to this by repeating the call as she flies. This is the “patrolling flight." While performing the “butterfly flight” display, the bird slowly descends from the maximum altitude and deliberately and slowly flaps its wings. When this is finished, the wings are closed and the bird dives back into the canopy. The Jamaican blackbird flies above the forest canopy while singing which again is unusual among woodland birds. The song flight is performed at irregular intervals. In addition, both sexes of the species perform three behavioral displays . There is little information about the territory size but it is estimated to be roughly 500 to 1200 ft. in diameter . (Barker, et al., 2013; Jamarillo and Burke, 1999; Orians, 1985; Skutch, 1996)

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

Home Range

There is currently no information on the size of the home range.

Communication and Perception

Like other tropical monogamous songbirds, the male and female have a similar number of vocalizations. The male has seven while the female apparently has six. Although it has not been previously noted in the published literature, the species does seem to perform vocal duets. (Hoyer, 2014; Odom, et al., 2015; Orians, 1985)

• Communication Channels
• visual
• acoustic
• chemical

• Other Communication Modes
• duets

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Due to the gaping mechanism adopted by the Jamaican blackbird, it is successful in filling the feeding niche that has evolved in the absence of trunk foragers and bromeliad probing. The Jamaican blackbird is also known locally as "wild pine sergeant" because it forages among bromeliads. These birds also forage amongst lichens, ferns, mosses and other epiphytes. While foraging, in movements likened to those of a woodpecker or woodcreeper, it climbs along vines, vertical trunks and moves outwards among branches near the trunk. The bird has three main foraging behaviors which are probing, gleaning, and pecking. Probing with their long and narrow bill is most extensively used. The species feeds on snails, spiders, a wide diversity of insects such as grasshoppers, beetles, ants, cockroaches, beetle larvae, termites, millipedes, sow bugs, small frogs, and lizards. The Jamaican blackbird occasionally eats fruit but only rarely eats smaller berries. Unlike other paired tropical birds, foraging was generally not done in pairs but alone. (Cruz, 1978; Raffaelle, et al., 1998; Raffaelle, et al., 2003; Skutch, 1996)

• Primary Diet
• carnivore
  • eats terrestrial vertebrates
  • insectivore
  • eats non-insect arthropods
  • molluscivore
• herbivore
  • frugivore
• omnivore

• Animal Foods
• amphibians
• reptiles
• insects
• terrestrial non-insect arthropods
• mollusks

• Plant Foods
• fruit

Predation

There is no information about the predators of the species. The dense and isolated habitat may be seen as an anti-predator adaptation. It is reasonable to believe that other bird species and reptiles are nest predators.

Ecosystem Roles

The Jamaican blackbird has not been extensively studied and ecosystem roles have not been identified. It is safe to assume that the Jamaican blackbird plays some role in seed dispersal. It is also insectivorous but it does not feed among the cultivated areas, thus lowering the possibility of it acting to control agricultural pests.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

The elusiveness of Jamaican blackbirds has made them a must-see on the list of many avid bird watchers as well as ornithologists. This then adds to the bird watching ecotourism industry of the country.

• Positive Impacts
• ecotourism
• research and education

Economic Importance for Humans: Negative

There are no adverse impacts of Jamaican blackbirds on humans.

Conservation Status

Jamaican blackbirds are endangered. The population is estimated to consist of approximately 2,500 to 9,999 individuals. However, more work is needed to better estimate the remaining number of individuals, identify threats to the population, and protect critical habitats. ("Important Bird Areas in the Caribbean -Jamaica", 2016)

• IUCN Red List

  Endangered

• US Migratory Bird Act

  No special status

• US Federal List

  No special status

• CITES

  No special status

Other Comments

Although Jamaican birds are generally sedentary, some pairs are known to migrate to lower elevations during the winter season. (Jamarillo and Burke, 1999)

Contributors

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

References

2016. "Important Bird Areas in the Caribbean -Jamaica" (On-line). Birdlife International. Accessed March 04, 2016 at http://www.birdlife.org/datazone/userfiles/file/IBAs/CaribCntryPDFs/jamaica.pdf.

Barker, K., S. Lanyon, K. Burns, J. Klicka, I. Lovette, A. Powell. 2013. A comprehensive species-level molecular phylogeny of the New World blackbirds (Icteridae). Molecular Phylogenetics and Evolution, 71: 2-19.

Bond, J. 1993. Birds of the West Indies. New York, NY 10003: Houghton Mifflin Company.

Cruz, A. 1978. Adaptive Evolution of the Jamaican Blackbird Nesopsar niggerimus. Ornis Scandinavica (Scandinavian Journal of Orinthology), 9: 130-137.

Downer, A., R. Sutton. 1990. Birds of Jamaica- A Photographic Field Guide. Cambridge, U.S.A.: Cambridge University Press.

Hoyer, R. 2014. "Nesopsar niggerimus" (On-line). Accessed May 02, 2016 at www.xeno-canto.org.

Jamarillo, A., P. Burke. 1999. New World Blackbirds:The Icterids. 41 William Street, Princeton, NJ 08540: Princeton University Press.

Lanyon, S., K. Omland. 1999. A Molecular Phylogeny of the Blackbirds (Icteridae): Five Lineages Revealed by Cytochrome-B Sequence Data. The Auk, 116: 629-639.

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.

Orians, G. 1985. Blackbirds of the Americas. Tokyo, Japan: University of Washington Press.

Raffaelle, H., J. Wiley, O. Garrido, A. Keith, J. Raffaelle. 1998. A Guide to the Birds of the West Indies. 41 William Street, Princeton, NJ 08540: Princeton University Press.

Raffaelle, H., J. Wiley, O. Garrido, A. Keith, J. Raffaelle. 2003. Princeton Field Guides: Birds of the West Indies. 41 William Street, Princeton, NJ 08540: Princeton University Press.

Skutch, A. 1996. Orioles, Blackbirds, and Their Kin. Arizona, USA: The University of Arizona Press.