Nature scrapbook: Blue jays

blue jay

And all the day the blue-jay calls through­out the autumn lands. The words of poet William Wilfred Campbell still ring true today. Loud and brash, blue jays are especially boisterous in Sep­tember and October when on the move in loose flocks through cottage country. They vary greatly in number from year to year, depend­ing on whether there’s enough food around to stick it out through a northern winter or they have to join other jays picking their way to the movable feast in the central and southern US.

Nutty obsessions

While jays sometimes feed on the likes of rodents, bats, and birds, their destinies and destinations are determined by beechnuts, hazelnuts, and acorns. In the fall, the almost 30-cm-long bird will often fly one to two kilometres to a good stand of oak or beech, cram its throat and beak with up to five acorns or 15 beechnuts, and return home to stash its loot. In times of plenty, an indus­trious couple might deposit a winter store of up to 10,000 acorns and nuts in tree holes and cracked logs, allowing the pair to settle in their nesting territory year round.

Fleeing famine

Oak, beech, and hazel produce bumper crops roughly every other year, but relatively little in between, sending more jays packing. The vast majority of migrants hatched only months earlier; without time to establish territories for stashing their suppers, they move south, where they can forage all winter.

On the road

Unlike many songbirds, jays migrate by day (in the morning, mostly) rather than at night, possibly because they’re strong fliers and less vulnerable to birds of prey and daytime wind turbulence. Flocks of five to 30 cruise up to 300 metres above the treetops. They usually touch down around noon to stock up on nuts, seeds, and berries to power their flight, calling often as they forage through the woods for the rest of the day.

Blue jay way

When migrants reach Lake Erie, their flocks build into the hundreds and make their way south. About 440,000 blue jays were counted last autumn at the Holiday Beach hawk watch, south of Windsor, with more than 50,000 streaming past in a single day.

Healthy country living

Since West Nile virus arrived in Ontario in 2001, it has hit blue jays and crows, members of the same family, much harder than most birds. But the mosquitoes that primarily spread the disease thrive mainly in the urban areas of southern Ontario, so the birds of cottage country have been less heavily affected.