This is a crop of my best shot, nearly my last one of the tail end of the flock as they got far enough away that the camera focusing on the water sort of had the birds in a similar focal plane. Unfortunately these are a little over-exposed as I was expecting the birds to be higher with light sky behind them, not dark water.
The next pics are montages of individual birds cropped out of multiple images as I panned through the flock. These 4 birds were in a little sub-group, I cut out each individual to make it easier to evaluate each one.
The next 2 individuals are from 3 later frames.
Here's the last 4 birds in the flock (3 of which are pictured in the lead photo)
Not surprisingly, Tim's shots are a lot sharper.
Finally a group of Long-billed Dowitchers that flew past at first light. Unlike the swallows, they were a Tiscornia tick for me.
That also says nothing of the improbability of mis-identifying Rough-winged or Cliff Swallows as Caves and then subsequently photographing Caves an hour later. In medical trials this idea is that of being prospective, meaning that you have a theory and then instead of applying it backwards to a set of data, you measure how it works going forward to prove that you are not just forcing your theory onto a past set of data. When it works going forward (i.e. subsequent birds that we identify as Caves that we photograph as Caves) that is strong support of the original theory (of being able to use binoculars and telescopes to identify birds, not just a shotgun, er I mean camera).
Oh and by the way, even if you think it's hard to photograph a swallow, it's actually harder.