It's too bad neither of those aircraft have red-painted empennage (tails). Of course, a little processing in post could change that state and then you would have some formation flying with the RTH. I'm tempted to try it ... but I'm lazy.
That's quite an intimate (natural) shot of the killdeer, largely due to that superb down-to-earth technique. You actually got a Tree swallow in flight with a heavy 600mm zoom lens! Studying for exams, while taxing, has certainly not blunted your chops with a camera. I saw a small group pf Tree swallows today and the thought of following them in flight with my camera was an endeavour just too daunting to consider. Oddly enough, I was staring across an empty expanse, seeing nothing, and then suddenly, as if by magic, a group of swallows just appeared out of nowhere. I noted that they must be using a dead topless tree trunk as a nesting place but the access hole was on the other side of the trunk.