At dusk we saw a large number of birds that appeared to be swooping and eating the bugs around a Big Box store. Larger birds, vaguely swallow shaped, and with a similar flight pattern. Distinguishing feature a light band 1/2 way down the underside of the wing. What are these birds?

Asked by ibstubro (18804) September 11th, 2015

They must put purple martins to shame as far as insects eaten, and I’d love to cultivate a flock.