The female was on a raised area in the pond. I heard another coot (the male) make a repetitive, single note call. He came from under the bank where I was, out of some reeds. Initially, I thought he had become aware of me and was sounding an alarm but the female did not move. In looking at the photographs later I noted her body appeared to change as the male approached. In the photos before the mating her body was plump, while when she was aware the male was approaching, her body slimmed down. She did not try to avoid the male, who took a circular route around the pond’s edge to approach her directly from behind. She appeared to ready herself. The male climbed onto her back and her head went under water. He was not on her back for long, possibly 10 seconds, I was not counting, then he raised his wings to climb down. She kept her head arched down but she came out of the water. He then moved away from her.