Tuesday, October 28, 2008

Corvids Part II - The Blue Jay

The Blue Jay (Cyanocitta cristata), belongs to the American (or ‘blue’) jays, which are not closely related to other jays (other than the Steller’s). Like other jays, this Corvidae is adaptable and aggressive; and is enlarging its habitat. It’s a medium sized bird, 9-12” long with a wingspan of some 13-17 inches. The color is medium blue to lavender on the crest and along the back, wings and tail while its face is white. Over a pale breast, it sports a thin necklace or ‘collar’ in black, which extends up and nearly around the head. Wing primaries and tail are barred in black, blue and white; eyes, strong bill and three-toed limbs are black.

Like other crested birds, it can raise or lower the crown of feathers. While feeding with other jays the crest is flattened to the head but if excited or aggressive the crest will be raised forward. It will bristle outward if the bird is frightened.

[edited to add: I just realized all photos are of birds with crests lowered! Thanks to Ecobirder's kind offer...I found a lovely shot of his...a Blue Jay with crest flying! NICE!!! Thanks again, Ecobirder! What a lovely little fluffy bird...must have been cold, huh?]

The Blue Jay occurs from southern Canada through eastern and central US, south to Florida and northeastern Texas. The western edge of the range stops about where the closely related Steller's Jay begins; though it sometimes hybridizes with that species. Recently, the range of the Blue Jay has extended northwestwards so that it is now a rare but regularly-seen winter visitor along the northern US and southern Canadian Pacific Coast, some stray birds may occur in California, now.

The Steller's Jay and the Blue Jay are the only New World jays that use mud in the construction of their nests. Many people dislike the Blue Jay because it is known to eat the eggs and nestlings of other birds. However, in an extensive study of Blue Jay feeding habits, only 1% of jays had evidence of eggs or birds in their stomachs. Most of the diet was composed of insects and nuts, but it can be aggressive towards other birds. They do not breed cooperatively, but conduct group social displays and mob predators and intruders, perhaps as members of a loosely organized neighborhood flock.

Tool use in birds is rare. Although no tool use has been reported for wild Blue Jays, captive jays used strips of newspaper to rake in food pellets from outside of their cages.

There is no blue in blue birds. As with other blue-hued birds, the Blue Jay's coloration is not derived by pigment, 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.

Like other corvids, this jay may learn to mimic human speech. Their voice is typical of most jays in being varied, but includs whistled notes and gurgling sounds, and the high-pitched jayer-jayer call, which increases in spead as the bird becomes more agitated. The most commonly recognized sound is the alarm call, which is a loud, almost gull-like scream…a shrill, harsh decending ‘jaaaay’, for which it is named. Another call sounds like a rusty pump handle, and another sounds like a bell. Blue jays also make rattling sounds. In the spring you can hear very soft singing. Listen here.

Notice jays can raise and lower that crest:

Killer jays do not keep crests down, either: typical jay behavior (while nesting)

This is an interesting shot with both a Steller's and
a Blue Jay.


Photos from Wikipedia


Kitt said...

A lot of people dislike blue jays, but they've always been one of my favorite birds, so bright and cheeky. They're a little rare this far west, so I always get a thrill when I see one or hear its rusty pump call.

Beverly said...

I agree, I like them...but it was kinda difficult when a pair nested in my yard when I lived in Denver. I swear, every time I went into the garden, I'd get dive-bombed! They are territorial little monsters when nesting!

I just love that sound, too...they're surprisingly musical, sometimes.

Part III will be Pinyon Jays...

RJ Flamingo said...

Really interesting. I like the blue jays, too and put sunflower seeds and peanuts out to keep them and the squirrels (temporarily) off the feeders. Anyway, I thought you might get a kick out of an older post of mine: