Before starting out, our group had a discussion about how to shoot in these conditions: set the white balance, set the ISO to 400 and shutter speed as high as we could without getting an under-exposure warning. As we were to find out, it was dark enough to warrant upping the ISO to 640 or 800 just to get in to the proximity of taking photos without camera shake being an issue.
Fortunately, most, if not all of us, had lenses with vibration reduction. As you know, I don't like shooting subjects over 400 ISO because of the potential to add noise to the image, but if you need the shot, you do what you need to do to get it!
At our first stop, we were lucky to spot a Great Heron who was happy to pose for us for quite a while! There was also a Green Heron tucked away in the branches of some trees, and there were encounters along the way that included a frog, another fishing Heron and a muskrat. That was a first! He was moving fast in the water, too, so composition took a little of a backstage just to record his presence.
You can see more of the group's excellent photos here: