Blue Jay
Cyanocitta cristata
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 (3.26 oz) in weight, while jays from warmer southern Florida averaged 73.7 g (2.60 oz). 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 will be fully raised. When frightened, the crest bristles outwards, brushlike. Voice: 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. Blue jays can also copy the cries of local hawks so well that it is sometimes difficult to tell which it is.
ID text from Wikipedia, CC BY-SA 4.0
Steller's Jay
Cyanocitta stelleri
Steller's jay is about 30–34 cm (12–13 in) long and weighs about 100–140 g (3.5–4.9 oz). Steller's jay shows a great deal of regional variation throughout its range. Blackish-brown-headed birds from the north gradually become bluer-headed farther south. Steller's jay has a more slender bill and longer legs than the blue jay and, in northern populations, has a much more pronounced crest. It is also somewhat larger than the blue jay's. The head is blackish-brown, black, or dark blue, depending on the subspecies of the bird, with lighter streaks on the forehead. Voice: Like other jays, Steller's jay has numerous and variable vocalizations. One common call is a harsh "SHACK-Sheck-sheck-sheck-sheck-sheck" series; another "skreeka! skreeka!" call sounds almost exactly like an old-fashioned pump handle; yet another is a soft, breathy "hoodle hoodle" whistle. Its alarm call is a harsh, nasal "wah".
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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