"Little Male" (to be known as 1st Male, Male1 or M1) has taken a mate and selected a nesting site. He is very aggressive in defending that site and his mate. He doesn't want me to pay any attention to her at all and will fly around, yelling, if I look her way. (I think he was also trying to impress her with his "protection skills") I call the female Female2 or F2 because she's the second female I've seen this season.
I saw a hawk drop down in that area and start walking around the lake shore. Both M1 and F2 mobbed it, flying around, screaming, diving at it. I thought that maybe it was after some eggs or chicks, but there weren't any. It was probably looking for something like that, though. Those two potential parents didn't let it stay in peace.
Meanwhile, "Second Male" (Male2 or M2) has taken over part of "Little Male's" former territory on the other side of the lake. Since M1 has a mate and has become more defensive, he makes a lot more noise to which M2 responds to very loudly, even flying over the area proclaiming it as his own. M1 seems to be staying only on the one side of the lake, probably to better defend the possible nesting site.