Our baby tree swallows are gone!  I don't know what happened to them, other than the fact that I know the swallows had slowed down on their feeding over the last couple of days.  When I got home from the hospital today, Tammy said that she no longer noticed any babies sticking their heads out of the nesting box anymore, nor were the parents coming to feed anymore.  Fearing the worst, I went out to monitor the box and found that it had no evidence of any birds in there.  I know that at least one of the babies was looking pretty big, and it has been about the minimum amount of time for swallows to fledge, so I am left with the assumption that they all grew up and left.  I had expected to see at least a couple of the babies not survive, but from what I can see so far, they all did.  I haven't cleaned out the nesting box yet, just in case the swallows do need to come back, but if we don't see them in the next week or so, I'll clean out the box.