Blue Jay

Lore & Background

The name jay derives from the bird's noisy, garrulous nature and has been applied to many other birds of the same family, which are also mostly gregarious. Jays are also called jaybirds. The blue jay was first described as Pica glandaria cærulea cristata in English naturalist Mark Catesby's 1731 publication. It was later described as Corvus cristatus in Carl Linnaeus' 1758 edition of Systema Naturae.

In the 19th century, the jay was described by French ornithologist Charles Lucien Bonaparte in 1838 as Cyanocorax cristatus, and given its modern scientific name Cyanocitta cristata by Hugh Edwin Strickland in 1845. The genus name Cyanocitta derives from the Greek words kyaneos (blue) and kitta and kissa (chattering bird, jay), and the term 'blue chatterer' refers to the bright blue plumage of the head, nape, back, and tail. The specific name cristata (crested, tufted) derives from Latin referring to the prominent blue crest.

Reader's Guide

The blue jay measures 22–30 cm (9–12 in) from bill to tail and weighs 70–100 g (2.5–3.5 oz), with a wingspan of 34–43 cm (13–17 in). Consistent with Bergmann's rule, jays from Connecticut averaged 92.4 g in weight, while jays from warmer southern Florida averaged 73.7 g. There is a pronounced crest on the head which may be raised or lowered according to mood. Its plumage is lavender-blue to mid-blue in the crest, back, wings, and tail, and its face is white.

The underside is off-white and the neck is collared with black. The wing primaries and tail are strongly barred with black, sky-blue, and white. The bill, legs, and eyes are all black. Males and females are almost identical, but the male is slightly larger.

The black plumage on its nape, face, and throat varies extensively between individuals. The blue jay's coloration is not derived from pigments but is the result of light interference due to the internal structure of the feathers; the actual pigment in its feathers is melanin. It feeds mainly on seeds and nuts, such as acorns, which it may hide to eat later; soft fruits; arthropods; and occasionally small vertebrates. It typically gleans food from trees, shrubs, and the ground, and sometimes hawks insects from the air.

Blue jays can be very aggressive to other birds; they sometimes raid nests and have even been found to have decapitated other birds. It builds an open cup nest in the branches of a tree; both sexes participate. The clutch may be two to seven eggs, which are bluish or light brown with darker brown spots. Young are altricial, and are brooded by the female for 8–12 days after hatching.

They may stay with their parents for one to two months. The blue jay is a noisy, bold, and aggressive passerine. It is a moderately slow flier (roughly 32–40 km/h or 20–25 mph) when unprovoked. It flies with body and tail held level, with slow wing beats.

Its slow flying speeds make this species easy prey for hawks and owls when it flies in open areas. Diverse predators may prey on jay eggs and young up to their fledgling stage, including tree squirrels, snakes, cats, crows, raccoons, opossums, other jays and possibly many of the same birds of prey who attack adults. The blue jay can be beneficial to other bird species, as it may chase predatory birds, such as hawks and owls, and will scream if it sees a predator within its territory.

Did You Know?

• The blue jay's coloration is structural, not pigment-based; if a blue feather is crushed, the blue disappears because the internal structure is destroyed.
• Blue jays can hybridize with Steller's jays where their ranges overlap, and in 2023 a hybrid between a male blue jay and a female green jay was found in Texas.
• The northernmost subspecies C. c. bromia is migratory, and thousands of blue jays have been observed migrating in flocks along the Great Lakes and Atlantic coasts.