A flock of Red-winged Blackbirds flies past the rising moon while on their way to an evening roost site in the cattails.
Behind the lens.
While camping in Arizona one winter, we noticed the blackbirds flocking in each night. Right after sunset, groups numbering in the dozens would flock in together. Flying at full speed, they'd dive into the cattails at the head of our small lake and roost there for the night.
So the next evening, we kayaked out and parked in front of the cattails, and waited. The sun set, the full moon rose, and the blackbirds started arriving.
I kept my camera pointed at the moon, and I pressed the shutter every time a flock flew across my view. Out of 20-30 frames, this was the only image I got that had a bird in front of the moon.
A little observation, a little planning -- and a little luck.