Green Jay Cyanocorax yncas Scientific name definitions

The Green Jay is a conspicuous and visually-striking species occupying two disjunct geographic ranges in the western hemisphere. Its expanding northern population occurs from southern Texas down through eastern Mexico to Belize, Guatemala, and Honduras, and in a second, narrower band along the Pacific Slope of Mexico. Its South American population extends from northeastern Venezuela west and then south along the Andes Mountains of Venezuela, Colombia, Ecuador, Peru, and northwest Bolivia.

Preferring dense woodlands with continuous canopy cover, the Green Jay avoids large open areas. It occurs in a wide array of woodland types including thornscrub and brushlands in southern Texas, forested islands along the Yucatán peninsula, and montane forests in the Venezuelan Andes. Although deforestation and agricultural intensification have reduced forests throughout its range, the Green Jay will occupy citrus groves and pine plantations with nearby forest cover.

The Green Jay hunts in family flocks, examining foraging areas using short flights between trees and hopping when inspecting a single tree. Flocks search trees from ground to trunk in spiral paths, with special attention paid to dead and rotting branches. Its diet consists of insects, seeds, fruit, small lizards, and frogs. Like other corvids (Corvidae), it is a common nest predator, taking both eggs and young nestlings.

Recent genetic analyses, along with known differences in appearance, behavior, and habitat preferences among the two populations may justify future splitting into northern and southern species. Perhaps most compelling is the contrast in breeding behavior. Throughout its geographic range, Green Jay family flocks retain nonbreeding yearlings until the end of the next breeding season. While the yearling members of South American flocks feed nestlings and help maintain the nest site, yearlings in the northern population contribute to territory defense only. It is hypothesized that the retention of young without direct assistance towards parental care represents an early evolutionary step towards the cooperative breeding system used by South American Green Jays (see Breeding).

The Green Jay remains relatively understudied but offers intriguing scientific opportunities. Large gaps in basic information include breeding success, diet, energetics, habitat requirements, morphology, and survival. In Texas, continued northward range expansion will bring the species into new vegetation communities and force unfamiliar species interactions (e.g., with the Blue Jay (Cyanocitta cristata)). Additional questions linger regarding the effect of cowbird parasitism on local populations. Interactions between the Green Jay and Giant Cowbird (Molothrus oryzivorus) are likely to increase as the latter colonizes new environments in South America.