Strange behaviour

Production Editor Matt Merritt writes:
One of the benefits of patch-watching in an area where spectacular rarities are few is that it makes you look that little bit harder at some of the commoner, more everyday species, so that you suddenly start to notice how often behaviour diverges from textbook norms.
The Easter weekend was a case in point. Late on Friday, I spent some time watching a Kestrel at my local country park. At least, I started off thinking it was a Kestrel, based on its shape and the fact that it seemed the only realistic possibility. After 10 minutes, I wasn't so sure. It spent the whole of that time soaring high in the sky, apparently chasing insects like a Hobby. It was silhouetted, so colour was no guide, and I started to wonder whether I was seeing a very early arrival. Finally, though, it moved lower and closer and, just as I was able to make out the plumage of a female Kestrel, it confirmed things for me by hovering and plunging to the ground.
The following day, out looking for Blackcaps and Willow Warblers, I noticed two Chaffinches doing their best to get mistaken for flycatchers. From perches high in a silver birch, they repeatedly darted out a few yards to snatch insects before returning to the same spot. I've seen this sort of thing before, but not by more than one bird at a time and not for such a prolonged period (15 minutes or so). This pair were clearly determined to make the most of a glut of gnats brought out by the warm weather.
The final incident was the best of the bunch. A couple of weeks ago at one of my regular haunts, Swithland Reservoir, a male Grey Wagtail seemed to be particularly bothered by the wing mirrors of cars parked on the dam, repeatedly landing on them in a rather agitated state and apparently challenging his reflection head-on. Although his mate looked on unconcerned, it was all a bit worrying, because small birds and glass don't really mix.
Yesterday, though, things had changed a little. The pair were still in the same spot, and had become bolder and bolder, regularly venturing to within five or six feet of me (I've usually found Grey Wagtails much more nervous than Pieds). Best of all, the male seemed to have lost his fixation with the mirrors, while his mate landed on them once or twice, but just to peer calmly into the car. Then, apparently satisfied that there was nothing of interest there, she flitted onto the roof, and ran back and forth picking off all the insects she could find.
Fast learners, wagtails, obviously. Even meals on wheels aren't beyond them.