Blue Jays: Masters of Imitation

Nov 8, 2017

 

Credit Brian Kushner/Audubon Photography Awards

I recently spent a few days at a cabin nestled in some dense boreal forest in downeast Maine, where I had a chance to spend some quality time with an underappreciated species: the Blue Jay. At one point, from inside the cabin I heard a clear and perfect Sharp-shinned Hawk call, causing me to look outside, just in time to see a Blue Jay making the call from the deck railing. 

As I watched, he followed that with a spot-on Broad-winged Hawk. The bird kept this pattern for every visit to the feeder over the next few days—Sharp-shinned call, grab some food, Broad-winged call, then fly off.

 


Blue Jays are so good at imitating hawks, especially Red-shouldered Hawks, that I have to be careful about identifying hawks that I didn’t actually see. They can do perfect Red-tailed and Cooper’s Hawks as well. I once heard an Osprey calling in Falmouth in January, a time of year when our Ospreys should be in Venezuela, but, as you’ve probably guessed, it turned out to be a Blue Jay. They’re like the Rich Little of backyard birds. I’ve gotten a little wiser over the years and can use context clues to discern fact from fiction, real Red-shoulder from Blue Jay. And, I can sometimes tell when migrant Blue Jays have arrived at the sanctuary by the hawks they imitate. When in October I suddenly hear a jay imitating a Broad-winged Hawk after a spring and summer hearing none, I know that bird is new in town.

Of the various hypotheses put forth to explain why Blue Jays imitate hawks, the only one that makes much sense, or has support from the literature, is that they do it to scare other birds and generally stir things up. There’s at least one case in the literature where a jay used a hawk call to scare a grackle into dropping its food, which the jay promptly stole.

While many jay sounds can be deceptive, I’ve learned one well enough to make use of it in a sort of birder’s version of a parlor trick. I’ve figured out that when I hear this jay call, the jay is likely being chased by a Cooper’s Hawk. I have more than once announced in hushed tones that a Cooper’s Hawk must be near after hearing it, just seconds before the hawk appears and invariably streaks across our view. It’s a great way to impress the uninitiated.

You may have noticed a lot of Blue Jays this fall. Around here, jays have a strong connection with acorns, and it seems to be a good acorn year across the Cape, despite a third year of gypsy moth defoliation. In years with few acorns, the jays will move on, leaving us bereft of their colorful and vocal presence in the otherwise quiet winter woods. In acorn-laden years like this, jays from further north may move in for the winter, their daytime migrations often quite obvious along the coast.

Credit Heather Bashow / https://plus.google.com/117221529703984186591

Jays don’t just eat acorns, they obsess over them. And today’s acorn collections turn into tomorrow’s oak forests. A couple of researchers, Carter Johnson and Curtis Adkisson, once documented the prodigious oak planting abilities of Blue Jays. They discovered that 50 jays could transport and cache 150,000 acorns in 28 days, which is about 110 acorns per day for each bird. A single bird may cache 5000 in a year. I reckon that’s enough to get them on an episode of Hoarders. Because they often cache the acorns in wet soil suitable for germination, jays have been credited with replanting the hardwood forests northwards after the retreat of the last glaciers.

So, yes, they’re loud. Yes, they eat the eggs and young of songbirds. And yes, they eat all your bird seed and drive off the smaller birds. But I suggest you learn to appreciate these most colorful members of the crow family, because they’re smart, they’re good looking, and they plant a lot of trees. So the next time you’re enjoying the shade of your backyard oak trees, why not thank a jay and fill that feeder up one more time.