This is much tougher than I thought it would be and I knew it wasn't going to be easy. After a long time trying these are my two best efforts. Will try again on a cooler day I think and with a sharper lens.
Nice job David. I was just looking at your shutter speed and then mine, and even at 1/2000th on mine those wings are still blurry. These guys are flapping it away at some amazing speeds.