A reader emailed inquiring as to where do the Niles Pond swans go during the winter months. The Niles Pond swans are Mute Swans (Cygnus olor) and they are neither mute nor migratory. They do not fly south in the true sense of a great migratory distance traveled, but do move around between bodies of water, and may move to a slightly warmer region.
Mute Swans swans grunt, snort, and hiss and their wingbeats make a beautiful throbbing sound when flying. See previous GMG posts about the Niles Pond Mute Swans ~