BIRDwatch

BLUE JAY

By Cecily Nabors

Noisy and bold, Blue Jays demand the limelight. Their apt scientific name, Cyanocitta cristata, means “blue bird with a crest.” These birds are instantly identifiable. Brilliant plumage plus a habit of announcing their entrance with a raucous call guarantee that attention will be paid. The blue in their feathers is not a pigment but a trick: Prismatic cells within the feathers scatter the light on the surface, reflecting blue to our eyes. In low light, those bright-blue feathers gray into twilight hues. Jays and crows are in the same family. Like other members of their family, male and female Blue Jays have the same plumage coloration. Shades of blue predominate, with black barring and white tips on wings and tails. The black bridle across the face and neck varies, and can make individuals recognizable. In our Mid-Atlantic area, we see jays all year round, but many do migrate in loose flocks. However, Blue Jay migration is hard to predict and not well understood by scientists. Some individual birds have been shown to migrate one year but stay put the next. Blue Jays like open woodlands and forest edges, so they’re quite at home in our well-treed suburban yards and parks. Jays often perform as an avian alarm system, warning of predators. Other birds take note when jays give their harsh calls; perhaps a hawk or owl is nearby. Our smart jays use that advantage: When they zoom into the feeder area, yelling “Jay, jay.” the other birds flee, giving the jays first dibs at the feast. Blue Jays also frequently imitate hawks. When a Red-shouldered Hawk seems to be calling from an unlikely position, the searcher may then hear a “Jay jay!” call that feels like “Made you look!” Is a Blue Jay always a loudmouth? No. They also make soft, melodious calls that sound like “wheedle dee.” And if you hear something like a squeaky pump-handle, look around for a nearby patch of telltale blue. Blue Jays often mate for life, staying together throughout the year. Males and females build the nests together, usually in the crotch of a tree. The female incubates the eggs and broods the young; the male brings food. The young birds stay around the nest area and close by with their parents for much longer than most bird species; those big brains need time for training. The young are fed insects and larvae, but adult Blue Jays eat mostly nuts and seeds. They come readily to feeders, and prefer tray feeders or hopper feeders on a post rather than hanging feeders. They focus on peanuts, sunflower seeds, and suet, although with an omnivore’s attention to any target of opportunity. Blue Jays are reputed to eat eggs and nestlings of other birds, but little proof of that accusation has been shown in studies of jays’ stomach contents. What studies do show is that Blue Jays are assiduous planters of oak trees. They love acorns and store food in caches to eat later. The Cornell Lab of Ornithology reports that in one study, six jays wearing radio transmitters each cached 3,000–5,000 acorns one autumn. Surely they didn’t retrieve all of them. If you have an oak tree in your yard, you might have a Blue Jay to thank for it. If you don’t have an oak tree and have space to plant one, don’t wait for a jay to do it. Doug Tallamy, chair of the Department of Entomology and Wildlife Ecology at the University of Delaware, says that oaks support more species than any other trees. Jays and oaks: a great team for biodiversity. Plus, planting oak trees will make acorns available for jays of the future. Blue Jays have recovered well from their losses from West Nile virus. Their range stretches from the Atlantic west to the Rockies, and they’re extending north

and west. Bird counts show that the population is stable. That’s good news. We want to keep seeing and hearing these smart, feisty, beautiful birds. o

Cecily Nabors is a retired software manager who has been watching and counting birds for much of her life. She publishes the GoodNatured Observations blog at cecilynabors.com.