Nature Notes: Blue Jay
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By Ed Robinson
The term “jaybird” has long been a slang word to describe someone who was a bit crazy, lazy or stupid. But the term is also a nickname for the blue jay, and this bird is definitely not lacking in brains, hustle or common sense. A member of the Corvid family of birds, which includes crows, ravens and nutcrackers, the bold blue jays are known for their intelligence, vocal nature and an ability to adapt to dramatic changes in their environment.
Blue jays are a common sight across most of the US and southern Canada, and ornithologists recognize four subspecies whose territories have limited overlap. In Maine, we are used to seeing the largest of these, the Northern blue jay. The birds prefer to live in either hardwood or softwood forests, mostly along the edges, but they are equally at home living near human habitations, especially if bird feeders offer an array of desirable foods. While some Northern blue jays will migrate a few hundred miles south in winter (estimated at 20 percent of the population), most of them remain in place unless their normal food supplies are unavailable.
Male and female blue jays are quite similar in coloration, the primary difference being a slightly larger male in adulthood. Their upper bodies are mostly lovely shades of blue with an off-white chest and underparts. The blue color in the jay’s feathers comes from a brown pigment called melanin, and the color we see is due to light scattering off the uneven surface structure of the feathers. Wing and tail feathers display blue, white and black. The bill, eyes and legs are black. The bird wears a black collar around its neck, and at certain times displays a prominent blue crest or crown with black trim. The crest is most often displayed when the bird is excited or is showing aggression or fear.
While the blue jay has a preference for all kinds of seeds and nuts, particularly acorns, it regularly eats fruits, insects and plant material. Field crops like corn may be on the menu. They have also been observed eating carrion and raiding the nests of other birds for eggs and nestlings. Unlike most birds, the blue jay will store nuts for later consumption. Radio-collared birds have been tracked hiding up to 6,000 acorns in an autumn season. Not surprisingly, this habit plays a role in the seeding of new oak trees. At bird feeders, blue jays favor high energy peanuts, suet and sunflower seeds.
Breeding season runs from March into July, with courtship displays that include the male singing and posturing with his feathers on display, aerial chases and offering food to his favored lady. Once paired, the birds mate for life and both sexes are involved with nest building and raising their young. The nest will be in the shape of a cup, and is most often found 10-30 feet off the ground in dense trees such as conifers to provide shelter from winged predators. The clutch will typically contain four to five eggs in soft blue or light brown colors with brown spots. The female will sit on the eggs for 14-18 days and after hatching, the chicks are fed by both parents for two to three weeks before they fledge and leave the nest. Young birds may remain with their parents into the autumn, after which they scatter, presumably to avoid competition for winter food sources.
Blue jays will reach up to 12 inches in length with wings that spread 18 inches to allow flight up to 25 mph. Despite weighing only three to four ounces, they can be quite aggressive toward other birds and even humans when protecting their nests or food sources. A wide range of predators will take blue jays or their eggs for food including raptors, squirrels, crows, raccoons, opossums and snakes. Other birds may benefit from the presence of blue jays because they are quick to sound alarm calls when they spot danger.
Like other Corvids, blue jays have a range of vocalizations and are capable of mimicking other birds or even human speech. Among themselves when there is no danger, jays use a series of quiet chirps, clicks, whirrs, whines and squeaks. They are able to whistle, perhaps copying the calls of other birds. If they are agitated or displaying aggressive behavior, they make a high pitched “jeer-jeer” sound. When alarmed, they also make a piercing scream that comes close to the call of a gull.
In general, birds are not possessed of large brains, but the Corvid family are capable of surprising ingenuity. They are known to drop acorns and beech nuts on rocks or highways in hopes of cracking the shells. Blue jays are known to make a call like a red-tailed hawk as they swoop toward a bird feeder, with the obvious intent of scaring other birds away so they can grab a few morsels. In captivity, blue jays have been observed using scraps of paper to move bits of food closer to their cages so they can grab a snack. They have also been known to try opening the latches on cages. When food is available, and danger lurks, the jay will carry several pieces at one time to a safe perch or hiding place, using a special pouch in their throat and their long bill.
Blue jays are capable of relatively long life spans, with documented cases of birds reaching 17 years in the wild and 26 years in captivity. Normal life span is probably much lower given all the risks that they face in the natural world. Studies have shown that domestic or wild cats and dogs cause a great deal of mortality in areas of human population. The birds are also susceptible to West Nile virus. Bird counts by the North American Breeding Bird Survey have shown the blue jay population to have fallen by nearly 30 percent in that last 50 years. With an estimated population over 13 million birds in the US and Canada, they are not considered threatened at this time.