Many water lily species have leaves which float right on the surface of the water. A few, like the Sacred Lotus and Spadderdock extend their leaves well above the water surface.
This image was taken in April. All the leaves appear nice and healthy and sit up straight and high out of the water. Waterfowl on the pond at this time consists almost exclusively of Wood Duck. Most of the females are sitting on eggs at this point so the males are the main ones out on the water. Notice what good cover the leaves provide if they need to quickly hide from a predator.
Not having followed pond life in the past as closely as I have this year, the yellow pond lily has surprised me. In this photo from the end of May, some of the leaves are already showing evidence of dried up dead areas. Despite that, the leaves still provide substantial cover for the ducks if needed. In fact, it was still difficult to spot Wood Ducks swimming around on the pond unless they were well out in the open.
I took this photo a couple of days ago. Notice how the Spadderdock leaves have almost all collapsed and sit much lower on the water. Early in the spring, it would have been difficult to see the Great Blue Heron because the leaves would have been up around his shoulders.
I took this picture the same day as the last one. Notice how if these Wood Duck young were among the leaves, they would not be nearly as well hidden. This is the most young ducks I have seen together in a while (I counted thirteen) and I think they are from many different clutches. What struck me was that their life cycle is in kind of a lockstep with the growth cycle of the lily plants. When the ducks are young and cannot fly, the leaves provide good cover. By the time the leaves no longer provide very good cover, the ducks can fly.
I have no idea why the lily pads on the far shore seem to be in such better health. They are still standing high and don't appear to have many dead areas on them. It isn't that there is more shade there because that shoreline receives sun almost all day. When I started visiting ponds it was winter and the lilies were not visible. I haven't got a clue what happens to them from now until winter.