Refugee Bluebirds?

Late this afternoon in Harahan, I heard the distinctive mellow notes of Eastern Bluebirds overhead.  A glance upward revealed a loose flock of five, headed approximately westward. 

Bluebirds winter only in very small numbers south of Lake Pontchartrain, and typically not in such an urban context.  My guess is that they were new arrivals, prospecting for habitat, driven south from St. Tammany or somewhere else to the north by the cold snap.  Such opportunistic cold weather southward retreats are well known, though more often discussed for waterfowl (shifting south as water freezes over) and boreal finches and raptors (searching for food).  In our area Killdeer are perhaps most often identified making such movements; during last winter's January cold snap, a flock of a thousand was reported on the Chalmette Battlefield during the battle reenactment.  Mid-winter southward movements have also been documented for Yellow-rumped Warblers.

Good birding,

Peter