Amblycercus holosericeus

Geographic Range

Yellow-billed caciques can be found throughout much of the neotropics. They are found in the Yucatan peninsula of Mexico, through Central America and into the mountainous regions of South America, including Colombia, Venezuela, Bolivia, and Ecuador.

• Biogeographic Regions
• neotropical neotropical
  • native native

Habitat

Yellow-billed caciques live at various elevations throughout their geographic range. Typically they are found at elevations of 200 to 1,800 m above sea level. They have been observed at elevations up to 6,000 m in Venezuela.

Yellow-billed cacique habitat consists of thick stands of overgrown brush in lower altitudes. In mountainous regions, they commonly seek refuge in large bamboo thickets that cover the forest floor. They commonly live deep inside thickets and brush in order to protect themselves from predators.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

Physical Description

Yellow-billed caciques are large song birds. The body is completely black in both males and females. Males, however, have a more lustrous shine to their feathers than females. Both sexes also have a characteristic beak which is a whitish-yellow color. Their eyes are vibrant yellow as well. They are different from other caciques in the fact that they are the only ones who are open-nest builders. That is, they build an open-topped, cup–shaped nest in which to lay their eggs. They range in size from 56.7 to 70.9 g and from 21.6 to 25.4 cm in length, males are slightly larger than females.

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

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful

Reproduction

Yellow-billed caciques are seasonally monogamous. Males and females form a bond for the breeding season.

• Mating System
• monogamous monogamous

Yellow-billed cacique breeding season varies geographically. Breeding season in Costa Rica is between the months of January and June. Eggs have been observed as early as December in Ecuador. Throughout much of South America mating takes place from November to April. Females lay from 1 to 5 eggs in a clutch.

Nesting behavior also varies geographically. Populations that live in lowland areas in Central America have nesting behavior that is different from populations in mountainous regions of south America. Lowland populations tend to build their nests inside large, dense thickets of bamboo, which are nearly impassable and provide protection from predators.

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

Yellow-billed caciques defend nesting territories and care for their young until independence. Males mainly defend nesting territories and the young, while females mainly incubate and feed the young. When the female is away from the nest, the male guards it.

• Parental Investment
• female parental care female parental care
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • male
• post-independence association with parents

Lifespan/Longevity

Lifespan in yellow-billed caciques is not known, but other icterids live to maximum lifespans of from 6 to 20 years.

Behavior

Solitary and sedentary in nature, yellow-billed caciques try to remain secluded in thickets and brush. They only travel out of thickets for food from high tree branches. They are different from other caciques in how they build their nests, which are built with an open cup shape. Nests are a combination of vines and leaf fibers woven together and are located off of the ground. Typically individuals are found alone, in a pair, or as part of small family groups during breeding season.

• Key Behaviors
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary

Home Range

Home range sizes in yellow-billed caciques are not known.

Communication and Perception

Males and females communicate through song patterns known as duets. The male begins with a churring sound. The female responds with a distinct call. The female also will whistle and chip to alert the male of potential hazards to the nest (i.e. approaching predators). The male has a more melodic sound in its chirp than females do.

• Communication Channels
• visual visual
• acoustic acoustic

• Other Communication Modes
• duets duets

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

Food Habits

Yellow-billed caciques are omnivorous. They feed generally on fruits, especially the seed pods of trees in the genus Inga . Yellow-billed caciques also use their sharp and narrow beaks to drill into bark and sugarcane stalks to search for various types of insects. They use special muscle groups to open their bills against pressure. This allows them to widen holes in order to remove any insects or seeds that they find.

• Primary Diet
• omnivore omnivore

• Animal Foods
• insects

• Plant Foods
• fruit

Predation

Yellow-billed caciques have adapted to avoid predators in the way that they choose their habitat. They build their nests and spend most of their time inside thick stands of brush or bamboo, protecting them from many, larger predators.

Ecosystem Roles

Yellow-billed caciques help to disperse the seeds of fruits they eat.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Yellow-billed caciques are important members of the ecosystems in which they live.

Economic Importance for Humans: Negative

There are no known adverse effects of yellow-billed caciques on humans.

Conservation Status

According to the IUCN Red List, Amblycercus holosericeus is considered "Least Concern." Yellow-billed caciques are found throughout a wide range and populations seem stable.

Additional Links

Encyclopedia of Life

Contributors

Andrew Jordan (author), Centre College, Grant Wallace (author), Centre College, Stephanie Fabritius (editor, instructor), Centre College, Tanya Dewey (editor), Animal Diversity Web.

References

Brown, W., S. Hilty. 1986. Birds of Colombia . Princeton, NewJersey: Princeton University Press.

Eaton, M. 2006. A Phylogenetic Perspective on the Evolution of Chromatic Ultraviolet Plumage Coloration in Grackles and Allies(Icteridae). Auk , 123/1: 211-234. Accessed April 03, 2009 at www.bioone.org/doi/full/10.1642/0004-8038%7 .

Greeney, H., D. Jaffe, O. Manzaba. 2008. Incubation Behavior of the Yellow-billed Cacique. Ornitologíz Colombiana , 7: 83-87. Accessed April 07, 2009 at http://www.ornotologízcomlombiana.org/oc7/Greeneytal.pdf7 .

Kratter, A. 1993. Geographic Variation in the Yellow-billed Cacique, Amblycercus holosericeus. Condor , 95/3: 641-651. Accessed April 07, 2009 at http://www.JSTOR.org/stable/info/1369607?seq=17 .

Lunk, W. 2009. Cacique. Groilier Multimedia Encyclopedia . Accessed April 07, 2009 at <http://gme.grolier.com/cgi-bin/article?assetid=0047970-0>. .

Ridgely, R., G. Tudor. 1989. The Birds of South America . Austin, TX: University of Texas Press.

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

Stager, K. 2009. Cacique (bird). Encyclopedia Americana . Groiler Online. Accessed April 07, 2009 at http://ea-ada.grolier.com/cgi-bin/article?assetid=0069700-00#citation .

de Magalhaes, J., J. Costa. 2010. "AnAge" (On-line). AnAge: The Animal Ageing and Longevity Database. Accessed January 25, 2010 at http://genomics.senescence.info/species/ .

2002. New World Blackbirds and Orioles. Pp. 301-323 in Grzimek's Animal Life Encyclopedia , Vol. 11, 2 Edition. Farminton Hills, MI: Gale Group.