I was walking down one of the paths early in the morning at the J.N. Ding Darling NWR. It was pretty dark on the sides of the path under the trees and mangroves. I heard Ibises moving in the lower branches of trees and in the mangroves but were mostly hidden by branches. Plus it was extremely dark to get a photo. Then I noticed this Yellow-crowned Night-Heron out in the open, standing under the branches. It was still very dark because the branches were blocking the rising sunlight. The Heron did not seem to be bothered and did not move, so I took a few shots and moved on. It was so dark where the Heron was, my shutter speed was very very slow, so I shot a series of bursts and purposely underexposed to get my shutter speed up. I did not want to raise my ISO, because the Canon camera I was using gets more “noise” at higher ISO’s. It was easier to work on sharpness later. I was using a 300mm f/4 lens with a 1.4x teleconverter giving me f/5.6 wide open. I have more success with having less noise from not using a high ISO, and under exposing a little and then brightening my image in Photoshop. Then adding a “high” pass sharpening technique in Photoshop and blending it in.
It’s not obvious from the photograph that you struggled with the lack of light. Sounds like you found a low-light technique that works for you.
You know that I don’t know much about birds, but this is one that I’ve found in Austin:
https://portraitsofwildflowers.wordpress.com/2012/01/28/and-blue/
Over the years I have come up with a series of Photoshop techniques that usually work. But then again, sometimes it does not! I commend you on your knowledge on the subjects on your blog, wish I could remember more on what you show us! Very nice Yellow-crowned Night-Heron on the link you shared.