Two females!

Very interesting day in the field! The first nest I went to had TWO females on it! They were co exisiting peacefully...both were food begging tho I saw no male nearby. One was incubating ( the female who I have been watching there since April) and the other, perched on the nest edge. I tried to figure out what was going on.
The new female went into the nest cup and sat down right next to the other female, bumping her, pushing right up next to her. Odd.
Then she got up and started moving sticks. They both kept food begging loudly. The resident female got up and looked into the nest cup and appeared to be tending to chicks as the other female watched. After about 30 minutes of me scratching my head, the resident female looked at this other female, with her head cocked to the side...and she stood up, went over to the other female and chest bumped her off the nest. No real aggression, but a definite message to get lost. It was crazy! No male ever arrived and the resident female quit food begging after the other female visitor left. I guess they were food begging from each other! Another unusual behavior...what a year! I also counted a lot of chicks heads, including some wee ones, and watched a lot of feedings. Great day. Wish I had a video camera to document those two females!