Wild Mute Swans

Last spring we were surprised to spot two wild mute swans on Combes Pond and two more on Smiley's Pond. After a week or so, both pair disappeared, despite our hopes that Sheffield would have a breeding pair.
This morning, as a few snowflakes sifted out of high overcast over Mill Pond, we spotted four mute swans in a cove, keeping their distance from a mixture of gulls, Canada geese, and common mergansers. They appeared to be two pair, and judging from the bluffing of one as it guarded its mate, not at ease with each other.
Our weatherman predicts four to seven inches of snow here this afternoon and tonight, so we wonder if the approaching storm has delayed their progress south for the winter.