Green Jay Life History

Habitat

Habitat Open Woodlands

In South Texas, Green Jays inhabit woodlands and scrubby thickets, often along waterways. Typical trees in their preferred habitats are mesquite, Texas ebony, huisache, sabal palm, and anaqua, but they also visit fruit plantations, particularly of citrus. Farther south, in Middle and South America, Green Jays frequent many types of wooded habitats, from lowland forests and plantations to rainforests at higher elevations, especially where there are forest gaps.

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Food

Food Omnivore

Like most members of the crow family (Corvidae), Green Jays are omnivorous, eating a great variety of insects, small vertebrates, seeds, and fruit. Among insects, grasshoppers, crickets, bugs, caterpillars, and flies are common prey items. They also sometimes eat spiders, small lizards, and frogs, as well as eggs and nestlings of other bird species. Seeds of sabal palm, acacia, ebony, and prickly-ash may comprise important parts of the diet, particularly during colder weather, when insects are less available. Green Jays are agile, active foragers. They forage in family groups, moving in the same direction together as each explores a different tree or shrub, scanning for insects or other food before hopping or flying to a new vantage point. Some individuals work from the base of a tree to the crown, searching systematically before moving to the next tree. On the ground, Green Jays move leaf litter with their bills, exposing arthropods, which they capture with a pounce and peck. They may also feed at outbreaks of caterpillars or visit dead trees to feed on abundant insects.

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Nesting

Nest Placement

Nest Tree

Male and female select the nest site together. Nests average about 8.5 feet high in dense, brushy vegetation.

Nest Description

Male and female construct the nest together, a thin-walled cup of sticks lined with roots, moss, grasses, vines, and leaves. Nests average 8.7 inches across and 4 inches tall, with interior cup 3.5 inches across and 2.4 inches deep.

Nesting Facts
Egg Description:Pale greenish white with dark spots near large end.
Condition at Hatching:Naked and helpless.
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Behavior

Behavior Foliage Gleaner

Green Jays are highly social and usually found in family flocks that consist of a nesting pair, their offspring from the previous nesting season, and more recent fledglings. In the mornings and evenings during the breeding season, younger birds greet the adults by calling and hopping. Pairs are monogamous throughout the year and remain in constant contact throughout the breeding season. Courting adults may preen one another while giving soft calls, and females solicit courtship feeding by begging. Females indicate readiness for mating by bobbing and fluffing out the body plumage. Male and female share incubation duties, and both feed the nestlings at the nest. The mother cares for the fledglings after they leave the nest, while the father spends more time with the yearlings. The yearlings do not help feed their younger siblings but do patrol the edges of the territory, which averages about 40 acres in Texas. When predators or other Green Jays appear in the family’s territory, the yearling birds call loudly and may give chase, often making swooping dives at the intruder, sometimes with help from the male parent. As younger birds mature, after just over a year, the male parent joins them regularly on daily territorial patrols and eventually drives them away from the territory.

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Conservation

Conservation Low Concern

Green Jay populations in Texas grew an estimated 6.9% per year between 1966 and 2015 as the species’ range expanded northward, according to the North American Breeding Bird Survey. Overall, Texas is a small portion of the range, and the global population appears stable rather than increasing. Partners in Flight estimates a global breeding population of 880,000 and estimates 60,000 breed in the U.S. The group rates the Green Jay an 11 out of 20 on the Continental Concern Score, indicating it is a species of low conservation concern. Conservation challenges for this species include destruction of habitat, particularly native Tamaulipan brushland, which constitutes much of the species’ primary habitat in southern Texas and northeastern Mexico. Green Jays also take bait from traps set for mammals and are sometimes inadvertently killed in such traps.

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Credits

Gayou, Douglas C. (1995). Green Jay (Cyanocorax yncas), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A., and A. S. Love (2017). Longevity records of North American birds. Version 2017.1. Patuxent Wildlife Research Center, Bird Banding Laboratory, Laurel, MD, USA.

Partners in Flight (2017). Avian Conservation Assessment Database. 2017.

Rosenberg, K. V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M. Ruth, H. Stabins, J. Stanton, and T. Will (2016). Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2017). The North American Breeding Bird Survey, Results and Analysis 1966–2015. Version 2.07.2017. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, USA.

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