The attacking bird was extremely aggressive. He actually picked up a bird by the claws (not shown) and tossed it into the water, stomped on the birds, and tried to knock them out of the sky. One bird was cut on the leg. Meanwhile, the nesting pair tried to build up their nest, even carrying a large stick that had fallen into the water to add to the nest.
The private war was quite exciting to watch, but I kept hoping that none of the birds would be critically injured. (and I don't think they were) I am wondering if the birds were fighting over the nest or the female. The nest is quite popular and there might be a shortage of good nests nearby.
The female is the larger bird with a sort of brown necklace of feathers.
Please comment if you like or if you notice anything interesting about the behaviors of the birds.