I was lucky this past January at Bosque del Apache NWR in New Mexico to have a northeast breeze at sunrise. Lucky because I got good opportunities for flight shots, not so lucky to near freeze to death. Anyway, I had noticed that several of my friends, some of who post and moderate here, had just sold their Canon gear for Nikon gear to get better AF. I wanted to see if I could get good sharp images against a busy BG (any decent camera can make sharp flight images of big birds against a clean BG such as the sky) and made dozens of images that morning, with a satisfyingly large number of sharp ones. The shadow of the bird's head on its wing made this one of my favorites. Canon 7DII, Canon 100-400 f/4.5-5.6L IS II at 400mm, ISO 640, f/6.3, 1/2500, manual exposure.
Hi David, love the light in this, and I like the shadow of his head on the far wing. Nicely separated from the rest of the flock. You can post much larger which makes a huge difference with IQ.