Today when I was getting ready to go out and take some photos I thought to myself I think I am going to see something unusual today.
I walked down to the stream I almost always go to and as I started walking I began seeing common mergansers. There was a large group of common mergansers swimming in the stream. This might by name sound, um common, but for me it was unusual. I have seen common mergansers frequently but not in this location and not exhibiting the behaviors that they were.
They were hunting……. Mergansers dive under water to catch their prey. When I think of this the image that comes to mind is a bird is swimming along looking down through the water from above and then dives under when it sees something it wants to catch. This however is not what was going on. The mergansers were swimming along on top of the water like ducks but with their heads stuck in under the water so that their eyes were submerged for several seconds at a time. Then when they saw a prey item they would dive under and catch it.
The fact that they were swimming in a closely bunched group may have given the impression that they were hunting as a group. But that did not appear to be the case. I did not see any mergansers dive cooperatively to catch anything. They dove generally one at a time and succeeded or failed at catching their food individually. There was no combined effort or sharing of food. In fact when one merganser literally bit of more than he could chew, or gulp down fast. It became a free for all. There was no all for one and one for all. It was every merganser for them self. When the merganser who saw the fish first dove after it so did others as they saw it. Each trying to catch it first. Once on caught it and emerged from the water with it in its beak the others rushed in to try and steal it and it became a giant game of tackle the bird with the fish. In the end it appeared that the fish got away in the frenzy.
Now for me that is what I call an unusual sighting.