Whistling Swan Question

[RKD]

Could Whistling Swans still be migrating this late?

Yesterday heard a whistling sound and discovered very high in the sky a flock of  about 50 birds circling as if trying to gain elevation. This carried on long enough for me to get my binos from the house but even then it was hard to see colouring. They seemed dark but it could have been the lighting and distance. They were very vocal. Finally they formed a vee formation and flew off.

Although my waterfowl identifying skills are low I have seen and heard Whistling Swans before at close range but are there any other species it could have been?

[newfoundlander61]

Tundra Swans are currently on the move and there wing beats make a "whistling sound".

[thouc]

Whistling Swan refers to the North American subspecies of Tundra Swan (the other subspecies is Bewick's Swan of Eurasia).

And November is the peak fall migration time for Tundra Swans, and they are returning in March, with some overwintering along the north shore of Lake Erie.