In my almost 8 years of photographing wildlife at the Ridgefield NWR, in Washington state, I have never seen two American Bitterns at the same time, let alone out in the open and interacting with each other. To me, the bird on the left appears to be smaller and probably younger–maybe even the other bird’s offspring (but this may be an inaccurate assessment). [One commenter suggested that both birds may be juveniles]. The bird on the right did not walk around a lot in the 18 minutes I watched this interaction. But the smaller bird several times walked away about 10 feet then back toward the other bird. Each time the small bird approached the larger one and got close to it, the larger one seemed to tense up, open and close its mouth, and try to stare it down. This didn’t seem like the behavior I would expect of a parent toward a youngster of its own. Several times when the two got close, they looked as if they might break out into a scuffle–but they never did. The video shows one of the occurrences where the younger bird approaches the older one. The birds were not in hunting mode since they were out in the open on the shore and a good ten feet from the water’s edge. The large bird spent the time basically pointing its bill into the air appearing to mimic tall grass–even though the grass was about 15 feet away. Overall, this was odd behavior for a single bird but observing both birds was a real treat.
As the small bird moves closer to the larger one, notice how the larger bird opens and closes its mouth. I get the feeling these two aren’t exactly friends.
I cropped the video and the quality suffered some. Best viewed at 720p and full screen. If the video freezes up after switching to 720p, restart the video from the beginning.