The Green Heron is one of the smaller herons and we seldom see them in Madison County. We were surprised to find two of them in the Killbuck Wetlands one August day. They were apparently passing through on their southward migration as we haven't seen them since.
In the photo above it is apparent that they are smaller than a Mallard duck as both heron and ducks look for food on the dam spillway.
Here's the long and short of it. Like most herons, the Green Herons have very flexible necks that are capable of considerable telescoping. Here we see two pictures of the same heron, with its neck pulled in and extended. This bird also seems to have been banded at some time.
The two herons were not a pair and there was a definite pecking order with one chasing off the other several times. This one was the lower-ranked one of the two.
Both were intent on hunting, probably to "refill their tanks" for the next leg of their journey.