Question: Are some Killdeers migrating in pairs?

Killdeer in flight: is it flying solo, or with a friend? Photo by Kenn Kaufman.

Early March: Killdeers just started showing up in the area a few days ago.  I've seen them at about a dozen spots.  The thing that strikes me about them is that all the Killdeers I've seen have been in pairs.  So the question is: do they go through their courtship and form pairs very rapidly after they get here, or are they actually pairing up somewhere to the south of here, and arriving together? 

Killdeers don't leave northwest Ohio for very long.  Usually a few linger locally until mid-December, and the first returning birds are back by mid to late February.  They're common in winter just a few hundred miles to the south.  It would be plausible for them to form pairs on the wintering grounds.  The Birds of North America account for Killdeer doesn't shed any light on this.  It does say that Killdeers in the South may remain in pairs all year, and that those in the north may have the same mate for several years in a row. 

I guess I'll have to watch the arriving Killdeers more closely next year, to see if there's active chasing and courting on the day they arrive, or if the birds come in looking like established couples already.  But I'd be interested to hear from anyone who has more insight into this question.