I had one chance at this. The Heron was sitting on the marsh bank almost right next to me. The tall grass hid him perfect. For some reason he jumped up and took off.
Here was the only open spot for a photograph. Tall grasses and reeds were on either side. I think I grabbed the shot through an open hole in the reeds.
I probably should have missed this since I was using my backup Tamron 18-400mm lens. A lot of range options, but slow to grab focus.