[Tweeters] Merganser behavior

[Ellen Cohen]

This behavior was observed by a friend who has a home not far from Luhr beach.  Has anyone else observed this?  Is this typical or unusual behavior?  Is it possible that these were red breasted mergansers & not common, and would that make a difference in this type of behavior?  Thanks for your collective knowledge!
We saw some interesting behavior in front of our Olympia place. First, there was a group of about 100 common mergansers (which is probably the largest group of these birds I've ever seen) near the shore. Even more interesting was that they were in a long curved line and, presumably, when they found a school of fish, they made a semi-circle and swam very fast, almost running on top of the water. Sometimes they did this in the direction of the shore and I thought they were herding fish  and trapping them between their line and the shore. I didn't know that mergansers had cooperative group hunting. Apparently they were successful in finding fish because numerous seals took notice and tried to join in the fun. So it was all very interesting.

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