The Green Jay (Cyanocorax yncas) is a bird species of the New World jays, which exhibits distinct regional variations within its large but discontinuous range. The Green Jays of the Northern population are smaller, at 25–29 cm (10–11.5 in), than the South American birds, at 29.5–34.3 cm (11.7–13.6 in). Weight ranges from 66 to 110 grams (2.3–3.9 oz).[2] They have feathers of yellowish-white with blue tips on the top of the head, cheeks and nape, though some taxa have more blue than others. In South American populations, the crown can appear almost entirely white, with less extensive blue. A black bib forms a thick band up to the sides of the head as well as a stripe through the eye line and one above it. The breast and underparts typically are bright to dull yellow, or strongly green-tinged in the far northernmost part of its range. The upper parts are rich green. It has large nasal bristles that form a distinct tuft in some subspecies, but are less developed in others. The color of the iris ranges from dark brownish to bright yellow depending on the subspecies.