Fifteen years ago in the Zoological Garden, living a peaceful and tranquil life, were four swans:  two white swans (males) and a pair of black swans (male and female), which produced infertile eggs. About a year ago one of the black swans died, and for a period of time the black female wandered alone and lonely, before eventually joining the two white swans. Throughout the entire past year the three swans lived a peaceful social life. However, about a month ago one of the white swans began to wander around alone in the internal parking lot, near the keepers’ dining room.  Each time the keepers returned him to the grass area, but he kept coming back, without any perceptible reason.  He even began to swim in a small water tub in the area, and it seemed that he was beginning to look upon the parking lot as his permanent home. The mystery was solved after a few days:  it seems that the other white (male) swan and the black female had begun to establish a bond, and our hero was no longer a part of the former threesome. All that we can now do is to follow and see how it all develops.