It was the morning after another recent, successful spring owl migration night, bringing our total for that week to 20 caught, banded and released.
But now with the owls probably all sitting well camouflaged in treetops, I was focused on the birds inhaling sunflower seeds at my feeder. At times, there would be six of them on the feeder downing 10 to 15 seeds each before they flew off.
Although blue jays do eat insects, and occasionally other bird eggs and nestlings, their diet mostly is seeds and nuts, with sunflower seeds many of us put out, along with acorns they find in the wild, being major contributors to their diets. I’ve not seen it, but apparently they can stash five or more acorns in their throat pouch and mouth. I assume they are small ones, not the big ones I often see.
While many people do not like blue jays for this hog-like eating behavior, I find them quite interesting. But I’m also disappointed I have not given more serious thought before as to how they are digesting all of those seeds.
Thinking about it more than I previously had, I was quite sure they weren’t cracking the sunflower seeds open and hulling them as they put them in their mouths. So, I initially assumed they must just swallow them and leave it up to their muscular gizzard, loaded with gritty sand, to break them open for further digestion. But that didn’t seem to make sense either, so I went online and got mixed info from different sites.
ADVERTISEMENT
I then decided to reach out to the two other nature columnists who write for the Star Tribune, Val Cunningham and Jim Williams. For the past couple years, I’ve tried to read Wednesday and Sunday morning editions, where one of them usually has a column in the E section. I’ve also communicated with them on stories we write, or vice-versa.
Val responded quickly. "I’d say that blue jays fill up their throat pouch with sunflower seeds, then fly off to hide them in a cache to eat later, or cough them up one by one to eat, after pounding open the shells, as opposed to swallowing them whole."
She then checked with another birding resource she relied upon and confirmed that seemed to be what they do.
I was kind of surprised, as I’d seen hundreds, perhaps thousands, of blue jays feeding during the years, but don’t recall observing any of them displaying this behavior. I have, however, watched many chickadees take a single sunflower seed, fly a short distance from the feeder, transfer it to their toes and then tap it until it breaks open. Guess I will need to watch blue jays more closely to witness them doing it for the seeds they temporarily store in a throat pouch.
Although having a reputation as being an aggressive feeder bird, blue jays are not as aggressive as other birds. For instance, I often have seen red-bellied woodpeckers on the feeder that seem to display dominance over blue jays on the same feeder.
Among their own kind, blue jays have quite complex social interactions, using both sounds and the raising of feathers on their crown to communicate. The higher up the crown, the more displeased they are. But they also are very committed, usually developing year-round, lifelong bonds with their mate.
And, even though their name implies they are blue, blue jays actually are not. The blue color we see is not because of a pigment, similar to the red in cardinals, but instead, the color is caused by microscopic structures in the feather that refract light similar to a prism, often referred to as iridescence.
Blue jays are vocal birds, able to squawk, but also able to mimic other birds, something I attribute to them being quite smart, since they are close relatives of crows. I can’t count how many times I have heard what I thought was a red-tailed hawk calling, only to have it turn out to be a blue jay.
ADVERTISEMENT
Although I consider blue jays to be year-round resident birds, some actually do migrate. And, even though quite large, blue jays can be picked off by the small woodland sharp-shinned or Cooper’s hawks, or by cats that humans allow to run free.
So, don’t begrudge blue jays inhaling your seeds, as they, too, must eat. And, make sure to keeps your cats from feeding on them.
