A cacophony of sweet bird calls added brightness to the sunny morning as my family pulled up to a yard full of bird feeders in Sax-Zim Bog Important Bird Area about an hour northwest of Duluth, Minn. As we watched, the dark line of fir trees came alive with movement, and soon the feeders were lined with the striking yellow, black, and white bodies of evening grosbeaks. After a dim look at just a few grosbeaks outside the Museum a few weeks ago, I was thrilled to see such a flashy flock!
Grosbeaks have a habit of descending on feeders in the morning, and then disappearing by midday. As we watched, groups of ten to twenty birds flushed off the feeders and disappeared into the forest behind us. The cacophony quieted, and we decided to move on.
Our next stop was another set of bird feeders on Admiral Road. Here, staff from the Friends of Sax-Zim Bog keep black oil sunflower seeds stocked, and smear peanut on logs and branches. As I stood up out of the car to get a better view, a soft gray bullet about the size of a robin zoomed right over my head!
Canada jays are one of the northern birds that draw people to Sax-Zim Bog. Here, on about 300 square miles of public and private land, the clay soils of an old glacial lake plain hold water, and the cold, wet climate has perpetuated a thick layer of peat on top. Bog species such as sedges, tamaracks, and black spruce give the landscape a scraggly look, and open areas provide good hunting grounds for rare species of owls. According to the Friends of Sax-Zim Bog at saxzim.org, it’s a “'magic mix’ of habitats that boreal birds love.”
It didn’t take long for the Canada jay and their mate to return to the feeders. They ignored the seeds, though, and went straight for a huge glob of peanut butter. Through my camera’s zoom, I watched a jay fill their mouth over and over with the sticky, energy-rich goo. Blue jays have a pouch in their throat they use to carry acorns and other food items. I couldn’t find a reliable resource describing the same thing in Canada jays, but I snapped a photo of a jay with their throat distended!
Canada jays are opportunistic omnivores, and they consume everything from small mammals, nestling birds, carrion, and arthropods to fungi, fruits, and seeds. They have been observed picking engorged winter ticks off the backs of moose. Anyone who has camped within their range knows that these “camp robbers” are not shy about snatching up a crust of bread off the picnic table, or nabbing a marshmallow before it can become a s’more.
The evening grosbeaks we saw earlier wander great distances to find good food sources in the winter, but Canada jays stay put. In order to survive, Canada jays hide away food all summer and fall. They coat mouthfuls of food in sticky saliva, then glue the boluses in tree crevices, under lichens, in evergreen needles, and behind the flaky bark of spruce and jack pine trees. A Canada jay may hide 1,000 separate caches of food in a single, 17-hour day. “Scatter-hoarding” is the technical term for this technique. “Canada jays have a memory like a Vegas card counter,” writes Joe Rankin in Northern Woodlands magazine, referring to the fact that the jays seem to be able to retrieve 80 percent of their food-filled saliva balls.
At least a portion of the lost 20 percent is due to spoilage. Some boreal tree species may contribute antibacterial compounds that help the food stored under their bark stay fresh. But that’s not enough. Cold temperatures are necessary to prevent cached food, even chunks of meat, from spoiling. One study in Algonquin Provincial Park, conducted by researchers at the University of Guelph in Ontario, found that freeze-thaw events in autumn have a “significant detrimental impact on the quality and/or quantity of cached food available to Canada jays” the following winter. At the southern edge of their range, the refrigerator is broken.
Soon, both Canada jays swooped from the feeding station, back over my head, and disappeared into the forest behind me. Were they taking peanut butter to their chicks? These intrepid birds nest in February and March! That’s one reason their food caches are so important. Those same researchers in Algonquin National Park have found that supplemental feeding by humans allows Canada jay chicks to grow faster and fledge earlier. Some people have worried that human-provided food doesn’t offer the same levels of protein and vitamins that birds are accustomed to from their wild diet, but the researchers found only positive impacts.
Globally, Canada jays are common, and seem to be doing fine in the northern reaches of their range. Here at their southern limits, those globs of peanut butter might be the key not only to seeing these beautiful birds today, but also in years to come.
Emily’s third book, Natural Connections3: A Web Endlessly Woven, is available to purchase at www.cablemuseum.org/books and at your local independent bookstore, too.
For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Winter Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.
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