Bird of the Month: Blue Jay
Blue Jay. Photo by Jeff Bryant.
By Roger Digges, CCAS Vice-President
One very common family of birds I haven’t discussed in this blog yet is the corvid family, perhaps the most intelligent group of birds living in our area. September’s bird of the month is one many of us have known since childhood, a bird which many people enjoy having at feeders because of their striking plumage and energy, while others resent them because they may drive other birds away from feeders.
Easily recognized by their blue, black and white plumage, most jays in our area live year-round in the US and southern Canada. Ironically, Blue Jay feathers are not actually blue. While a male Northern Cardinal’s striking red plumage and a male American Goldfinch’s brilliant yellow feathers are produced by pigments called carotenoids in the food these birds eat, there are no blue pigments in birds’ food. According to an April 28, 2016 article by the Smithsonian Institution, blue feathers in birds is caused by how light interacts with feathers and the arrangement of their protein molecules (keratin, the same molecules that make your fingernails). Different keratin structures create different shades of blue. While the melanin in these birds’ feathers is really brown, I’m still calling them Blue Jays. (Learn more about how keratin structure makes blue in bird feathers from Smithsonian Magazine here.)
Where can you find Blue Jays? On forest edges, preferably near oak trees, and in urban and suburban neighborhoods where there are oaks, bird feeders, bird baths, or other water features. In the wild, Blue Jays eat insects, acorns, nuts, fruits, grains, and very rarely (less than 1% of the time) the eggs or nestling of other birds. At feeders, Blue Jays love peanuts, but I should warn you, they can go through a 50-pound bag of peanuts in the shell in a surprisingly short time. They also eat black oil sunflower seeds and may eat suet.
While it’s true that a Blue Jay may clear out feeders as it flies in boldly and raucously, sometimes voicing a good imitation of a Red-tailed or Red-shouldered Hawk, both of which occasionally eat birds, the feeders are soon full of birds again. While jays have the reputation of being bullies because of birds fleeing from them, I’ve found that Mourning Doves are the ones who most often crowd out other birds from tray feeders.
If you have large trees in your yard or neighborhood, Blue Jays may have built nests near you. The male Blue Jay (hard to tell which is which) probably gathered most of the nest materials—live twigs, grass, and rootlets (collected from fallen trees, ditches, or even freshly dug graves). The female built the nest in the crotch of the tree or along one of the larger branches, 10 to 25 feet off the ground, an open cup of twigs and grass lined with rootlets. She would have laid 2 to 7 eggs that hatched within 17 to 18 days. During the first 8 to 12 days after the young hatched, the male would bring food for mother and nestlings while the pair (which mate for life) would feed them thereafter. After another 17 to 21 days, all the young would have left the nest together, but are still fed by their parents for a month or two. During that time, newly fledged Blue Jays are loud and insistent.
How are Blue Jays doing? While Blue Jays are common, their population numbers declined between 1966 and 2019 by 27%. Their greatest cause of death is attacks by cats and dogs. While there are still 17 million of them, you can help this bird best by keeping your cat indoors and watching your dog around any feeders you have. And planting oaks.