By Ann Hingas

UPDATE: West Nile Virus Killing Blue Jays In North America

Blue Jays are dependable visitors to back yard bird feeders, although "raider" would be a better term for this feisty and spectacular bird known for its aggressive behavior.

There are two striking characteristics about blue jays which draw human attention. First is their spectacular color--bright blue on top with white underside and a crested head. Second is the bird's variety of raucous calls and songs which often serve as alarms for other birds when a hawk or a cat or some other predator is in the area. They possess a wide variety of calls, and are able to mimic other birds.

If you have Blue Jjays visiting your feeder, you have probably heard one or more of them mimicking either a Red-shouldered Hawk or a Red-tailed Hawk. One of these blue beauties who visits my platform feeder daily has this trick mastered. More often that not, he/she begins mimicking a Red-shouldered Hawk when it is near the feeder. It sounds almost exactly like the hawk, but the copied, jay version doesn't have the "weight" of the real hawk voice. I haven't been able to determine if using this hawk call affords the jay any feeding advantages.

Blue Jays are also notorious raiders of other birds' nests. They will attack any bird in the immediate vicinity of their nest in the spring, as well as steal eggs, young birds and even nests. They like robin nests and often appropriate them for nesting. In fact, a Blue Jay nest looks much like a robin's nest--a large collection of sticks as a base. The inside of the nest is usually lined with grass.

The Blue Jay is a member of the Corvidae family which includes ravens, magpies, crows and a variety of other jays scattered throughout both North and South America. Blue Jays live throughout eastern North America from Manitoba all the way to Florida and the Gulf of Mexico. Although not usually considered to be a migratory species, some jays do migrate in winter, with northern birds replacing their relatives that summer further south.

Blue Jays are omnivorous, meaning they eat everything. About 75 percent of their diet is vegetable matter. This choice of diet is seasonal, as blue jays prefer insects, salamanders, tree frogs and even mice, according to some sources, during warm weather. Before blight hit the American chestnut tree, chestnuts were considered the blue jay food of choice; however, they like just about any kind of nut and are especially fond of acorns.

Blue Jays are aggressive, curious and large when compared to most of the other perching birds. Their cousins the ravens are the largest of the perching birds. If you've ever had a pair of jays nest near your house, you may have been attacked and pecked if you came too close to their nest. Young jays commonly collect brightly colored objects like bottle caps and pieces of aluminum foil and carry them about for awhile. Sometimes they try to peck open such objects, or they will use them as platforms and simply sit atop them until they get bored.

As noisy and aggressive as they can be, blue jays are very secretive during the nesting season. They pick nesting sites in thick cover and take circuitous routes through tangles of vines and shrubs to reach their nests. They prefer coniferous trees like pines and cedars for nesting sites when such trees are available. Around the nest, the jay abandons its loud calls and communicates with its mate in "whisper song." The so-called "whisper" song is used by other species, including the gray catbird, for example.

On the other hand, I get mail from urban bird feeding folk who find jays nesting on their porches or in rose trellises near the house where they co-exist with humans. Such close interaction with humans is not unusual among this family of birds, and most of the humans are surprised that these nesting jays dive bomb their pets and even the humans to protect their nests.

Blue Jays are monogamous, meaning pairs bond and remain together for life. The male courts the female by feeding her constantly and continues to do so while the female incubates four to six brown-spotted, greenish eggs. Both sexes have the same appearance, and young blue jays are gray-colored until they get their adult feathers.

As aggressive as the blue jay is, it is easy prey for hawks and owls when in the open, because it is a slow flier when compared to other perching birds. Its large size, about 12 inches from bill to tip of tail, also makes it an easy target for avian predators.

This is no doubt one reason for the Blue Jay's disdain for owls in particular. Owls are known to pluck jays from nests during the night. When jays spot an owl roosting during the daytime, they will dive bomb and peck it until the owl is forced to find a new roost. Fellow Corvidae family members behave similarly around owls. Crows are also known for their owl attacks.

Blue Jays are among our most beautiful and intelligent back yard visitors. Watch them and learn just how smart a bird can be.

Maryville College Blue Jay Resources
For a biological profile of the Blue Jay, Cyanocitta cristata, go to:
Click Here

For a biological profile of Stellar's Jay, click here.

Cornell University Laboratory of Ornithology Blue Jay profile

Cornell report on West Nile Virus

  Other readers' questions (including what one reader found to be an excellent baby bird food mixture she makes with dog food) about the baby birds they found in their yards: Click Here

Updated 6/22/03

Sources Used In Preparing This Story:

Hinde, R.A. , editor. Bird Vocalizations. Cambridge University Press. Cambridge. 1969.

Madge, Steve and Burn, Hilary. Crows and Jays. Houghton Mifflin Co., Boston. New York. 1994.

Peterson, Roger Tory. A Field Guide To The Birds. 2nd Revised edition. Houghton Mifflin Co. Boston. 1947.

Wetmore, Alexander. Song and Garden Birds of North America. National Geographic Society. Washington, D.C. 1964.

Welty, Joel Carl. The Life of Birds. 2nd edition. W.B. Saunders Co. Philadelphia. 1975.

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