|[Note Guidelines] Photographer's Note|
|This Blue Jay was out side our home waiting to get into the feeder on a very cold morning.|
The Blue Jay (Cyanocitta cristata) is a passerine bird, and a member of the family Corvidae native to North America. It belongs to the "blue" or American jays, which are, among the Corvidae, not closely related to other jays. It is adaptable, aggressive and omnivorous, and has been colonizing new habitat for many decades.
The Blue Jay measures 9-12 inches (22-30 cm) from bill to tail and weighs 2.47-3.53 ounces (70–100 g), with a wingspan of 13–17 in (34–43 cm). There is a pronounced crest on the head, a crown of feathers, which may be raised or lowered according to the bird's mood. When excited or aggressive, the crest may be fully raised. When frightened, the crest bristles outwards, brush like. When the bird is feeding among other jays or resting, the crest is flattened to the head.
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 which extends to the sides of the head. 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 nearly identical; males are slightly larger.
As with other blue-hued birds, the Blue Jay's coloration is not derived by pigments, but is the result of light refraction due to the internal structure of the feathers; if a blue feather is crushed, the blue disappears as the structure is destroyed. This is referred to as structural coloration.
Blue Jays have strong black bills used for cracking nuts, and acorns and for eating corn, grains and seeds, although they also eat insects such as beetles, grasshoppers, and caterpillars.
Blue Jays can make a large variety of sounds, and individuals may vary perceptibly in their calling style. Like other corvids, they may learn to mimic human speech. Their voice is typical of most jays in being varied, but the most commonly recognized sound is the alarm call, which is a loud, almost gull-like scream. There is also a high-pitched jayer-jayer call that increases in speed as the bird becomes more agitated. Blue Jays will use these calls to band together to mob potential predator such as hawks and drive them away from the jays' nests.
Blue Jays also have quiet, almost subliminal calls which they use among themselves in proximity. One of the most distinctive calls of this type is often referred to as the "rusty pump" owing to its squeaky resemblance to the sound of an old hand-operated water pump. The Blue Jay (and other corvids) are distinct from all other songbirds for using their call as a birdsong.
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