My sister, Susan Jenkins, is an avid birder and provided this almost exuberant identification: "Canvasback - cool bird - black & white body with red head and longish sloping bill. One in foreground, one in upper left corner and one in nearly upper right. The totally black ones with white bills are Coots (really! American Coots). The rest are mallard males and females. And the gulls? As improbable as it sounds, I think they are California gulls."