mute swan on nest in grayish rippled water - cygnus olor

140 160 200 240 additional adults africa america anatidae australasia average bill birds blue cygnus eurosiberia exceed extant family feathers females flying grayish head heaviest home introduced introductions iron knob large larger largest long male males mass match maturity member mute name native neck nest north olor orange-brown populations range rare rippled second southern species stained swan swans tannins though trumpeter visitor vocal water waterfowl white wingspan winter