I've been thinking about this a lot of late.
First, I swear...About 6 weeks ago I was going to post to COBirds a prediction that a Barn Swallow would be seen this year on a Colorado Christmas Bird Count. Probably John Martin. Well, I'll make the prediction now. Okay, I've just jinxed that particular outcome. Somewhere out there, Duane Nelson is poking voodoo needles in an effigy of me.
Large numbers of Barn Swallows remained last year into mid-October, with a few lingering into the first few days of November.
And there was something of a tardy departure, too, in 2011.
This is wild conjecture, but I think something big is going down with Barn Swallows in our region. Across the Northern Hemisphere, swallows are engaged in some dramatic range shifts. Like flocks of Northern Rough-winged Swallows wintering in Philadelphia. And think about the whole Cave Swallow phenomenon; that species wasn't on any Eastern birder's radar screen 25 years ago, and now it's annual in the hundreds.
Back to Colorado Barn Swallows. (Sorry, Hannah and Andrew's macaroni is boiling over as I type, and the cat won't leave me alone.) I've seen dependent young into the 2nd week of September the past 3 years, and on 2 visits this month to the Wyoming Hereford Ranch, I saw dependent young. Plus, there was that monster September roost (thousands of birds) in 2009-2011 in Boulder County.
Again, and to wrap up a rambling note, my speculation is that we're seeing some longer-term behavioral and range shift with Barn Swallows in our region. Let's pay attention, let's diligently eBird all our Barn Swallows for the rest of 2013, and, if one does waft down the Arkansas River on the John Martin CBC, you heard it here first.
Ted Floyd
Lafayette, Boulder County, Colo.