I think of American Coots as very common, uninteresting birds, and so I never photograph them. But I was intrigued by their diving maneuvers to obtain submerged vegetation, and stopped to watch them more closely on my walk along Los Gatos Creek in San Jose, CA the other day.
Coots seem to be very buoyant in the water; it takes work to submerge and they actively kick their feet against the water as they dive, quite unlike what Cormorants do.
Coots occupy a wide variety of wetland habitats throughout North and Central America, feeding on a variety of aquatic vegetation. But they are not fussy and will eat seeds or invertebrates they find on land as well. Typically, they forage in small groups, their lobed toes expanded to a web as they kick backward to propel them through the water, and then collapsing inward as they bring their foot forward again.
That lobed toe design comes in handy when Coots walk across muddy, marsh ground, preventing them from sinking down into it. And they assist Coots in taking off from water, when they need to use their feet to help lift their chunky bodies into the air.
Pretty useful, those funny feet!