They look like the same two that come every year. There is a big pond not too far from us in the country, and that is where alot of them are, so I think that is where they come from. They must see the water on the pool cover and decide to come over for a dip. We were right out there, and they were not afraid of us. I told by husband not to get too close when he was taking the pictures, but that did not even bother them. Even when we put the bread out there, they stayed. Now we won't see them again until next year.