The Northern Blue Jay: The Other Blue Bird

01/13/2023 By Sherry Thornburg

Blue Jay Facts

Diet: Omnivore – seeds, insects, and berries

Life span: The longest known life spans are 17.5 years in the wild and 26.25 years in captivity. The average wildlife span is believed to be 7 years.

Size: 10 to 12 in (25 to 30 cm)

Weight: 2.5 to 3.5 oz (70 to 100 g)

Habitat: Forests dwellers, but also live in suburban neighborhoods, cities and parks

Observing Blue Jays

One Spring a loud cry from my backyard came again. I dismissed it because I had NOT forgotten to feed the birds that morning. That little fuss-budget had no business complaining to me. Later, I went to the back window to see what was going on as it was still crying. White-wing Doves were cooing up in the Mimosa tree on one side as usual and at the top of the tree perched my neighborhood Blue Jay, making frantic calls like Paul Revere on his night ride to Concord. Considering the time of year, I had imagined this jubilant announcement involved his clutch hatching.

Northern Blue Jays are likely the most widely known backyard birds east of the Rockies alongside the Northern Cardinal. Their brilliant blue feathers, speckled wings, raised crest and black necklace (Bridle) make them easy to see, even in dense bush. The pigment in Blue Jay feathers is melanin, or brown. The blue we see is caused by modified cells on the surface of the feather barbs that scatter light. The black bridle across the face, nape, and throat seems to be unique to each bird, which may help Jays recognize one another.

How to Tell Male and Female Blue Jays Apart?

Long-time birders will laugh and say, “Only the Jays know.” The truth is, the males are a little bigger, but it’s hard to tell by size. The main difference is in social behavior. In February, love is in the air for these birds. If you see a group of Blue Jays, watch to see who leads. Courtship involves a flock of males following a single female from place to place. When perching, the males will bob their heads, and strike poses. The winner of this masculine beauty contest gets the girl.

If you observe these birds at nesting time, you will notice both gathering nest materials and building. Together, the Jays will build a few practice nests before settling on a final design. When agreed, the female will do most of the final work. She also does all the incubation while the male defends the nest and brings food. If you see a cat, dog or squirrel getting chased by a Blue Jay, it will be the male chasing, because the animal came too close to his mate.

Blue Jay Backyard Feeding Basics

If you put out water and feed where a large bird can get to it, Blue Jays will come. Their diet in the wild includes nuts, seeds and berries depending on the availability. They also are known to go after a wide variety of insects. Bringing Mr. and Mrs. Blue Jay into the yard is a great thing for gardens. I have also heard reports of Jays taking off with wasp nests to feed their young.

Blue Jays aren’t very picky. I have seen them eat sunflower seeds off my platform feeder and seed mixes. Once, I put out a nut and fruit mix, they were hooked and didn’t want anything else. Laying out a banquet table or even offering peanuts in the shell will make them love you. However, as a neighbor discovered, at certain times of the year, the Jays would snatch all the nuts in to store. He watched one carry off everything he had and bury them in a nearby park lawn. So yes, they store food in the fall, because they don’t migrate.

Add a Little Something Extra A negative you may have heard involves Blue Jays eating other bird’s nesting chicks and eggs. This is true, although it’s rare. Studies have been made, estimating only 1% of Blue Jays do this. Female Blue Jays and other nesting birds need calcium in the spring. Both sexes can benefit from extra minerals in the fall. Whether or not it will save a nest, giving your Blue Jays calcium as extra feed would not go amiss.

Calcium Recipe

Save eggshells after cooking, rinse them and bake in the oven at 250 degrees for 20 minutes. This cleaning and baking will eliminate harmful bacteria. Boiling the eggs does the same thing, however, the shells will still require baking if left out for long.
Crush the baked eggshells and place them on your feeder or on a separate tray if you want to see how birds receive it.

Do Blue Jays Migrate?

As I noted, Blue Jays are one of those birds that may or may not be migratory. They are listed as such. I saw them year-round when I lived in East Texas, Georgia, and Louisiana. But in late October through mid-January, they seem to disappear or visit rarely. In more northern climates, they are seen migrating in flocks as large at 250 or more, but this seems a matter of choice. Some will stay in the area they hatch all year, and some will migrate one year and not the next.

Nesting Season

As mentioned, Blue Jay courtship starts in February. A pair will build a few practice nests and then the final one within a week between 10 to 25 feet off the ground. They like the thick outer branches of forest trees. The female will lay two to seven bluish or light brown eggs with brownish spots. Incubation takes about 18 days.

Between 17 and 21 days, older nestlings can wander away on trial trips up to 15 feet before they fledge. After fledging, young birds will stay with their parents for another month or two.

There is a wide range in times recorded for nesting, fledgling and parenting. Blue Jays vary in how they deal with their young. In Southern climates, a pair may have two broods, so spacing between broods could be involved. Blue Jay juveniles have a greyish helmet look to their heads, as seen in picture 4. At a point of maturity, they go bald as you see in picture 5. When the feathers grow in, they will show adult coloring patterns with a distinctive bridle.

Nest Platform, Not Box

In cities and suburbs, Jays will nest on the ledges of buildings or your house eaves. Because they prefer open nesting, they won’t be tempted by a nest box. If you want to host a nesting pair, you will need a nest platform or shelf.

Birdhouses101.com suggests “an open birdhouse or nesting platform (shelf) to attract them. Provide a floor area of about 8 x 8 inches square with a ceiling also about 8 inches high. A sloping ceiling with open sides and front. Any birds who normally nest on trees are more likely to accept your platform.

To mimic the bird’s natural habits, place the shelf on a pole. Include a pole baffle to help keep out predators.

Jays and Their Calls

Despite their reputation for being aggressive, and I can attest to this, Jays are not alpha birds. Woodpeckers, Grackles, Mourning Doves, White-winged Doves, Northern Mockingbirds, and Northern Cardinals, and often squirrels seem to be above them in the feeder pecking order. See picture 5, where a woodpecker fusses at a young Jay to teach him his place. I have seen Jays look longingly at my feeder while a mob of White-wing Doves crowd them out.

In response, Jays have developed a secret weapon to run off the competition, an extensive vocabulary. Friends with feeders have told me of hawk cries in their yards. When they headed out to investigate, they found a Blue Jay making the noise. This mimicking tactic may have been developed for protection and to avoid confrontations. In the wild, their hawk imitations include Red-shouldered and Red-tailed hawk calls.

Final Word

Blue Jays are loud and vivacious, but they aren’t at the top of the songbird chain, so have developed inventive behaviors. They will use tools. It’s a rare thing, but it does happen at need. Captive Jays have been seen using paper to rake seeds back to them from outside of their cages. All this points to the Northern Blue Jay being a very special, contrary, and lovable bird.

Happy Birding