About of Blue Jay

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.Jays from

Connecticut averaged 92.4 g 3.26 oz in mass, while jays from southern Florida averaged 73.7 g .60 oz.There is a pronounced crest on the

head, a crown of feathers, which may be raised or lowered according to the birds mood. When excited or aggressive, the crest will be f

ully raised. When frightened, the crest bristles outwards, brushlike. When the bird is feeding among other jays or resting, the crest is

flattened on 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 almost identical, but the

male is slightly larger.As with most other blue-hued birds, the blue jays coloration is not derived from pigments but is the result of

light interference due to the internal structure of the feathers if a blue feather is crushed, the blue disappears because the structure

is destroyed.This is referred to as structural coloration.

The northernmost subspecies C c bromia is migratory, subject to necessity. It may withdraw several hundred kilometres south in the

northernmost parts of its range. Thousands of blue jays have been observed to migrate in flocks along the Great Lakes and Atlantic

coasts. It migrates during the daytime, in loose flocks of 5 to 250 birds. Much about their migratory behavior remains a mystery. Some

are present throughout winter in all parts of their range. Young jays may be more likely to migrate than adults, but many adults also

migrate. Some individual jays migrate south one year, stay north the next winter, and then migrate south again the next year. To date,

no one has concretely worked out why they migrate when they do. Likely, it is related to weather conditions and how abundant the winter

food sources are, which can determine whether other northern birds will move south.The blue jay occupies a variety of habitats within

its large range, from the pine woods of Florida to the spruce-fir forests of northern Ontario. It is less abundant in denser forests,

preferring mixed woodlands with oaks and beeches.It has expertly adapted to human activity, occurring in parks and residential areas,

and can adapt to wholesale deforestation with relative ease if human activity creates other means for the jays to get by.