Can Someone Identify this Bird?

 

These are the only pictures I've been able to get of them so far and neither hubby nor I can identify it.  Here is what I've observed so far:

These birds arrived in a flock of approximately 14.  At first they appeared about an hour after sunrise and an hour before sunset.  The glide overhead, in circles, as they head to their destination.  They are silent, which is why I haven't got many pictures ~ you don't know they are there.  Hubby thinks there is white on the wing feathers.

Anyone have any idea?