If you shoot often enough... and then some more and some more... sometimes you get lucky and come away with a happy accident. This is one of those times during which I was field-testing the new Sigma while focusing on a bird, which I assumed, from its call, was a Great Crested Flycatcher. It's actually a little hard to be certain, since I was trying to photograph it from below and the light wasn't exactly cooperative. A better birder would be able to discern all the subtleties and come up with an instant and unimpeachable identification, but I'm not that good so, when I looked at it, I had some head-scratching moments. For now, I'm calling it a Great Crested, but beyond any confusion over the ID, I'm positive that I can call it a pretty decent shot of an agile bird high in the tree tops capturing dinner.