Cyanocorax yncasgreen jay(Also: Inca jay)

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Geographic Range

There are two distinct populations of the Green Jay. The first is found north of the Rio Grande river in southern Texas to north central Honduras. The second population stretches from Colombia and Venezuela south through eastern Ecuador and Peru to Bolivia.

Habitat

The Texas Green Jay prefers open woodland, dense secondary growth, and bushy thickets dominated by mesquite. This jay is also found in citrus groves. Middle American populations prefer humid forests, rain forests, lowlands, plantations, and mountains. In South America the Green Jay is found in humid montane forest and forest borders, clearings, and secondary woodland.

Physical Description

The Green Jay is a long-tailed bird with a short crest. It is similar in size to a Blue Jay. Its wings, however, are shorter and more rounded. The Texas Green Jay has stiff, short deep blue nasal and frontal plumes. Its forehead, crown, and nape are white to bluish white. The feathers of the mantle, back, rump, and uppertail-coverts are deep green and sometimes tinged with blue. The breast and remaining underparts are yellow to yellow-green. Individuals from South America are a little larger and with longer nasal and frontal plumes that form a bushy crest.

Reproduction

The Green Jay practices monogamy, and pairs may form at any time during the year through the replacentment of an absent breeder. During the breeding season, a breeding pair rarely parts. Nests are usually in dense thickets, and trees and bushy shrubs are common nesting sites. Both the male and the female participate equally in choosing the nest site and building the nest. In Colombia, other members of a flock have occassionally been seen to participate in constructing the nest. The nest is cupped and its thin walls enable the eggs inside to be seen from below. Green Jay nests are constructed of thorny twigs and sticks and lined with roots, stems, moss, or dry leaves. Average clutch size is four grayish-white oval eggs. Incubation is performed only by the female and lasts 17 days. In Texas populations, the female is fed by the male at least six times a day. In South American populations, the female is fed by her mate; however, during the last three days of incubation she is fed by other flock members. After the chicks have hatched, the male continues to bring food to the nest for five days, then both parents share equally in bringing food to the chicks. Once the chicksd leave the nest, the female continues to feed them for three weeks. In Columbian flocks, all members cooperate in bringing food to the young and continue feeding the chicks for at least 20 days after they leave the nest.

  • Average eggs per season
    4
    AnAge

Lifespan/Longevity

Behavior

Texas populations are nonmigratory; however, there is a possibility of local migration in the Honduras population. The southern Texas population of Green Jay displays unusual behavior as it retains related nonbreeders in family flocks without cooperative breeding (helpers at the nest). These Texas flocks contain a breeding pair, the currrent year's nestlings, and the one year old non-breeding jays from the previous breeding season. The one year old nestlings provide territorial defense, but are ejected from flock when the current season's chicks have fledged. Colombian flocks have fixed year-round members that include helpers at the nest. Helpers at the nest may be needed in Colombia because food is less abundant due to habitat saturation. Usually, the more helpers a flock has, the higher the surviorship of its fledglings.

Communication and Perception

Food Habits

Green jays are omnivorous. Their basic diet consists of arthropods, vertebrates, seeds, and fruit. The bird forages in family flocks by examining new surroundings after hopping or short flights. When foraging, the bird moves from the lower portion of a tree in a spiral fashion up to the branches. The jay ocassionally hovers to inspect slender branches and clumps of moss. When foraging on the ground as an individual, it turns over dry leaves and twigs by sweeping its bill from side to side.

Economic Importance for Humans: Positive

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Economic Importance for Humans: Negative

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Conservation Status

The Green Jay holds no special status, but populations are limited by the amount of breeding habitat available. The bird is also vulnerable to traps set for other animals. The effects of trapping can be can be reduced by closing the traps at dusk or checking them at frequent intervals.

Other Comments

The Green Jay has a variety of calls, and flocks are often noisy and conspicuous in the breeding season. The species remains relatively unstudied.

Contributors

Marie S. Harris (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Gayou, Douglas, C.. The Birds of North America, No. 187, 1995.