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Why Blue Jays are blue
You can learn amazing things about a bird you’ve known your whole life — just by taking the time to watch
Contributed by Pete Dunne
Published: April 22, 2011 The snow ended shortly before noon. Sitting in my tree stand, cloaked in fresh powder, I was as close to being one with the surrounding North Jersey woodlands as a person could ever hope to be.
Then I saw the jay — 200 yards away, about 20 feet up, the only splash of color in a woodland gone black and white.
How, I marveled, can an electric-blue bird get away with such a telltale plumage in a landscape filled with hunting eyes?
Or put another way: What possible advantage could there be to being so conspicuous outside the breeding season?
Simply formulating these questions (and having the time to mull them over) led to a revelation. In the process, I gained respect for a bird I’ve watched all my life but only thought I knew.
As you know, birds come in a variety of colors and patterns. Some are showy, some are cryptic, and not a few are both. A number don eye-catching feathers during courtship. (They want to be seen and to impress.) But when breeding is over, they shed their courtin’ clothes and slip into something less flashy.
And then there is the Blue Jay. Male or female, young or old, it’s just about the biggest, brightest, most flamboyant, most conspicuous bird in the eastern forest — a visual treat to birders and a provocation to predators. It didn’t make sense. It seemed to go against logic. It...
Seems that just as a creature’s greatest strength is also its greatest point of vulnerability, a creature’s presumed liability can also serve as a strategic asset.
The great thing about sitting in a tree stand is the latitude it gives you to study and enjoy the world around you. When I’m birding, I’m more or less shopping, walking down the aisles, picking out the species, and putting them in the shopping cart of my mind.
Time on my side
When I’m in a tree stand, it’s like sitting down at the dinner table, a natural banquet. There is time to savor, time to get your fill, time to study the antics of chickadees, titmice, creepers, nuthatches, woodpeckers, and...
Jays. It’s a poor woodland that doesn’t host a troop in winter, and my favorite woodland is no exception. There were five jays in all. Age, sex, and genetic links were indeterminable, but I’m going to call them a family group.
In late summer, after fledging, I’ve watched certifiable family groups foraging in the forest. Because it makes sense that maintaining ties holds a strategic advantage, I’m inclined to speculate that the groups remain intact throughout the winter.
So for several days this past December, I got to watch this “family group.” In the morning, they’d head east. In the evening, I presume the same five jays would move through heading west, foraging as they went.
It was obvious they had a pattern, a routine. But it wasn’t until day four that I realized that there was more to it than that. There was also order. Their movements were not random; they were reasoned, patterned, disciplined.
The first thing I noticed was that at any given moment, most of the troop was stationary — not moving. Commonly, only one jay was shifting perches. Intrigued, I made it a point to keep an eye on each and every bird. Noting its position. Watching to see if more than one bird was ever changing position.
Once or twice, somebody jumped the gun — that is, two jays shifted position simultaneously. (More nearly, another bird made its move before another had settled.) But in general, one jay was moving while the others were watching — and typically, the bird that was moving was foraging on the forest floor, where acorns were the prize.
Then I realized that the movements weren’t the only variable that was deliberate; so too was the positioning. Some jays were high; some were low. One or more were ahead of the foraging bird; one or more were behind.
I don’t recall ever seeing the single bird ahead or behind the group. It was, in essence, within a perimeter that maintained its defensive configuration as the flock advanced — and maybe an offensive configuration, too: Perhaps the advance birds were searching for food to exploit. The deployment was as well suited for search-and-find as search-and-survive.
And, of course, all of the birds, whether they were foraging or standing guard, gained a measure of protection by having other members of the troop watching for danger.
I don’t know how discipline was maintained. I don’t know how the birds knew their assignments or how duties changed or were shared. (It’s plain that every member of the troop needed, at some point, to feed.)
I, after all, was stuck in my stand. The birds had a whole woodlot to exploit and moved on. My observation time was less than two hours.
But here’s the incredible thing, the marvelous thing: Had you asked me last November whether I was familiar with Blue Jays, I would have said, “Sure, been watching them all my life!”
And I have. I’ve just never known them. There’s a difference.
It was Thursday, the day after I had seen the distant jay and formulated my questions, when I began to piece together the foraging pattern. On Friday, from the same tree stand, I got to test it, to see whether the birds evidenced the same pattern and movements again. They did.
It was easy to keep the members of the troop in sight. The birds helped by staying, for the most part, in the open, on strategic perches. The stark woodlands helped, too, letting the electric-blue birds stand out. Even when the jays landed on the other side of a latticework of branches, the bright blue simply cut through.
That’s when it hit me like a bolt from the blue. That’s when I realized why jays are blue — or, at least, one reason why jays hold their flashy plumage year-round. It is precisely to stand out! It is, in the lingo of front-line troops and law-enforcement personnel, for “situational awareness.” It’s so every bird can know where the other members of the troop are at any moment.
A single all-blue bird in a stark winter landscape is vulnerable. But when a disciplined troop of birds coordinates their movements, the eye-catching color confers a strategic advantage.
And supporting this supposition (because, untested, that is all it is) is the foraging jays’ silence. Each could have communicated its whereabouts to the others vocally, as foraging chickadees, kinglets, and nuthatches do. But they did not. The only thing loud about them was their plumage.
It’s amazing, really, the things you can learn about a bird you’ve known your whole life just by spending time watching. I wonder how much I don’t know about all the other birds I’ve known all my life.
And what might be learned. If planners in the Pentagon want to figure out how to optimize offensive and defensive capacity in a three-dimensional world, they should hire ornithologists to study Blue Jays — to learn how the birds in blue do it.
And now that I have the situational awareness to understand that many things remain to be discovered about the birds I already know, I’m planning to spend more time bird watching and less time bird shopping.
Like this morning, when I went to check the feeders here at the Cape May Bird Observatory: Three Blue Jays were perched in the bush between me and the feeders. One was looking left. One was looking right. One was watching straight ahead. The building was guarding their six. The birds held this defensive position until I left.
Ha! Probably would have missed the significance of that back when I was just familiar with Blue Jays.
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Pete Dunne is vice president for natural history information for the New Jersey Audubon Society, director of the Cape May Bird Observatory, and the author of Prairie Spring: A Journey into the Heart of a Season (2009); Pete Dunne's Essential Field Guide Companion: A Comprehensive Resource for Identifying North American Birds (2006); Feather Quest: A North American Birder's Year (1999); and other books about birds and birdwatching.
Read more by Pete Dunne.
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