Sep 25 2009
Are you seeing a lot of blue jays lately? I am.
I used to think blue jays didn’t migrate because their range map shows them as year round in North America. Because I see them all year, I assumed I was observing the same individuals.
That was until one May morning at Lake Erie when I saw a long line of jays flying northeast along the shore. Chuck Tague told me they were flying to Canada but the lake was a big barrier.
As we watched, the jays turned north over the lake and hit a wall of air none of us could see. One by one they battled the invisible barrier. Finally they broke formation and flew back over land where they regrouped and again proceeded in a line, following the shore.
Other than similar observations at migration hot spots, blue jay migration is subtle if it occurs at all. Blue jays don’t have to leave home if they can store enough food for the winter. When they do decide to migrate, they travel during the day in small groups of 10 to 30 birds. It often doesn’t look like they’re migrating because the jays fly one at a time from tree to tree, a behavior that resembles foraging.
This fall blue jays are leaving Canada in droves because their winter food supply is low – too few acorns, beechnuts and hazelnuts.
I’m sure they’ll enjoy their time Pittsburgh. We have a bumper crop of acorns.
(photo by Chuck Tague)