Blue jays! Of all our year ‘round avian residents, few are as brilliantly plumaged as blue jays are. Indeed, for our color-starved eyes throughout the long and bleak wintertime, the blue jay’s color scheme is a welcome contrast to the mostly drab-colored landscape of winter.
As of late, I’ve been spending time at my parent’s home in the west central Minnesota town of Eagle Bend, which is about 50 miles south of Park Rapids. Their birdfeeder, hanging from a stout shepherd’s post complete with a metal conical-shaped predator guard, was empty, so I asked Dad where his birdseed was stored at in the garage.
On the coldest of mornings that the little town has seen in many years (-36!), I shoveled a thirty-foot path through the knee deep snow to get to the feeder. Minutes later, after locating Dad’s birdseed mixture in the garage inside a plastic five-gallon pail covered with a secure lid, I poured from an old grain scoop an ample supply of birdseed onto the fly-through hanging feeder, along with a dash of seed to the ground for good measure.
Mind you, the birdfeeder hadn’t been filled for nearly two weeks, and no birds were present, or had even shown themselves during the previous days as the feeder hung empty, but it didn’t take very long once I was back indoors that neighborhood birds had discovered Darlene and Lawrence Klemek’s birdfeeder was replete with seed once again. And the first birds to arrive? You guessed it, blue jays, and a pair at that.
Blue jays are one of two jays occurring in Minnesota. The other jay, the gray jay, sometimes called Canada jay, is a resident of the far northern regions of Minnesota and Canada as well as high elevations of the Rocky Mountains. Both species belong to a large family of birds, Corvidae, which also include familiar species to every Minnesotan—American crow, common raven, and another not-so-common corvid in many areas of Minnesota, the black-billed magpie.
It is oft written that the blue jay’s blue color isn’t really blue. In fact, a blue jay’s feathers contain no blue pigment whatsoever. The actual color of all those blue feathers is actually closer to black than blue. In a very complex manner, light is scattered throughout the feathers in much the same way that light scatters through a glass prism.
How it works, if you can wrap your mind around it, is hard to explain and conceptualize, but visible light makes contact with the feathers and passes through very small “nanostructures” of the feathers that are air-filled keratin (all feathers are made up of keratin, just like our own hair and finger and toenails). Interestingly, the sizes of the nanostructures matches exactly to that of the wavelength of blue light. And so, while the other colors of the spectrum pass through the feathers, the blue does not pass through. In fact, the blue color is instead is reflected, so what we see is blue.
To test this and see for yourself, if you were to grind up the feathers of a blue jay, the feathers would turn brownish because light can no longer reflect through the nanostructures. As well, if you were to take a blue feather of a blue jay and turn it around, you would not see all that much blue because the “prism” isn’t on the correct side anymore.
This “bending of the light” through seemingly blue feathers isn’t unique to blue jays. The same thing is true for another blue bird that occurs in Minnesota, albeit only half of the year—the eastern bluebird. Indigo buntings is another blueish bird that isn’t really blue after all. One can think of the blues we see in birds such as blue jays and bluebirds as merely a light show and not authentic pigment, because that’s exactly what this little light trick really is—Mother Nature’s light show.
Having a little color show up at our wintertime bird feeding stations is a delight for us to see. Other birds, too, provide color just as the beautiful blue jay does, but perhaps not quite as brilliantly. Evening grosbeaks come to mind, as do white-breasted nuthatches and red-breasted nuthatches, too. Still, it’s the blue jay that dazzles our eyesight the most in a landscape dominated by grays, browns, and white as we get out and enjoy the great outdoors.
Blane likes to hear from his readers. Email him your favorite outdoors experiences and wildlife encounters at firstname.lastname@example.org.