Birds of the Glebe, The Blue Jay

The Blue Jay, colourful, noisy and smart, keeps us company all winter long.
Photo: Jeanette Rive

By Jeanette Rive

Flashy, colourful, noisy, raucous, annoying, bullying and super-smart – all adjectives that apply to the Blue Jay. They are members of the Corvid family which includes ravens, crows and magpies, all known to be highly intelligent birds. They are great mimics and are especially good at imitating the call of a hawk, especially the Red-shouldered Hawk, either to warn other jays of danger or to trick other birds into thinking a hawk is nearby so that they can have sole access to a feeder!

The Blue Jay was one of the first American birds identified by early colonists. “They are abundantly more beautiful and finer featured than those in Europe,” noted one adventurer in 1709. It is the outstanding colouration that makes it so noticeable: the flash of white feathers as it flies off may startle a predator and give it a few extra moments to escape, but it’s the blue that is the most noticeable. However, their feathers are not actually blue! If you crush a Cardinal’s feather, for an example, it will be red because of the pigmentation. If you crush a Blue Jay’s feather, it will be brown from the brown pigment melanin. Their wings contain tiny pockets of air and keratin, the same protein found in human hair and nails. When light hits these pockets, all colours are absorbed except the blue which is refracted back to us. Indigo Bunting and Eastern Bluebird feathers have the same properties. If you find a feather from one of these birds and look at it under normal light conditions, it will appear blue; if you backlight the feather, it will appear brown.

Blue Jays are loud, especially in the fall, when they are flocking together and greeting other jays and exchanging information about food sources. If a Blue Jay squawked right in your ear, it would be deafening, so why isn’t it deafening to a bird when its bill is so close to its ear? As its jaw opens to make a sound, the external ear closes to shut out sound. In addition, birds can restore some damaged hearing by growing new hair cells inside their ears, which humans are not able to do, unfortunately.

Blue Jays engage in a behaviour unique to certain songbirds – it is called “anting.” A bird takes an ant and smears it along its feathers; some birds will take an ant “bath” to cover themselves with ants. Some believe the practice produces formic acid that provides some antiseptic protection for the birds, but many researchers now think that it’s done to make ants taste better! When ants detect danger, they release a noxious form of formic acid which tastes foul. When a jay rubs the insect on its feathers, it removes the bitter taste, and the ant becomes a better dinner.

Blue Jays are omnivorous: fruit, seeds, insects, mice and frogs can all be part of their diet, but their favourite food is the acorn. Their fondness for acorns goes back millenia, and Blue Jays are credited with helping to spread the growth of oak trees after the last glacial period. They engage in caching, just like the chickadee, hiding food on the ground and covering it with leaves or small rocks.

However, if they see that another bird is watching where it is being cached, they go back and move it. They can keep track of thousands of items – insects are retrieved within days, seeds and nuts can be cached for months.

Blue Jays are monogamous; the bond can last until one of the pair dies. They usually live for about seven years in the wild although one banded bird in Newfoundland lived well into its 20s. Both birds build the nest – a rather untidy cup high in a tree, made of twigs and bark, often decorated with bits of rags, string, even paper. They take parenting seriously, harassing and chasing away any predators, even though they themselves are known to rob the nests of smaller songbirds. The female lays three to six eggs that are light blue, light green or yellowish brown. Incubation, mostly the female’s task while the male supplies her with food, lasts about 18 days. The babies are ready to fledge about three weeks later though they will stay around the parents for about two months.

The Blue Jay is among the urban birds that spend the winter here instead of migrating south. The sight of its vivid blue against the snow is one of the delights of winter.

Jeanette Rive is a Glebe bird enthusiast and regular Glebe Report contributor.